Zoom lens system

ABSTRACT

There is provided a zoom lens of an inner focusing system which is capable of an auto-focusing operation and a manual focusing operation with a high precision. 
     A zoom lens system in which a movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam is arranged such that a ratio of an amount of rotation for focusing from infinity to closest to an amount of rotation for zooming from wide angle to telephoto in the focus cam is set within a predetermined range so that, when the sensitivity of a movement of an imaging point with respect to a movement of the focusing lens unit in the direction of the optical axis in the closest in-focus state is larger than that in the infinity in-focus state, the sensitivity of the movement of the imaging point with respect to the movement of the focusing lens unit in the rotational direction satisfies specific conditions.

The entire disclosure of Japanese Patent Application Nos. 8-27182 and 8-35994 including specifications, claims, drawings and summaries is incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a zoom lens and, more particularly, to a zoom lens attached to a so-called auto-focusing camera, video camera, or the like, which has a focus detection device, and moves a focusing lens unit in a photographing optical system in accordance with the detected defocus amount.

2. Related Background Art

In recent years, along with the wide spread use of auto-focusing cameras, various focusing systems such as a so-called inner focusing system, rear focusing system, and the like have been examined to make a focusing lens of a zoom lens compact.

However, in general, when a focusing system other than a so-called front focusing system is adopted, the lens driving amount for focusing changes upon a change in focal length. To solve this problem, Japanese Patent Application Laid-Open Nos. 4-293008 and 5-142475 assigned to the same assignee as the present invention proposed a method of realizing a so-called manual focusing operation in a zoom lens having a plurality of lens units including a focusing lens unit having both zooming and focusing functions. In this method, when a predetermined movement locus for zooming is expressed by the amount of movement of the lens units in the direction of the optical axis and the angle of rotation of a rotatable lens barrel, the movement locus of the focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam. With this arrangement, even when the amount of movement for focusing along the optical axis changes depending on the zooming state, the angle of rotation of the rotatable lens barrel for focusing is left unchanged, thus achieving a manual focusing operation.

However, when the above-mentioned zoom lens is applied to an auto-focusing camera system, which comprises focus detection means, storage means for storing the conversion coefficient γ and the correction coefficient ε used for calculating the lens driving amount Δx for focusing the focusing lens unit on the basis of the detected defocus amount ΔBf of a photographing optical system, and calculation means for calculating the lens driving amount Δx for focusing using the defocus amount ΔBf, the conversion coefficient γ, and the correction coefficient ε, problems associated with the storage capacity, calculation error, and the like are posed.

As in Japanese Patent Application Laid-Open Nos. 4-293008 and 5-142475 above, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 57-37307, 57-37308, 63-49715, 63-314511, 3-144411, 3-235908, 3-249717, 4-184402, 4-184403, 4-184404, 4-184405, 4-184406, 4-186207, 4-186208, 7-110446, and the like, in each of which the movement locus of the focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam, the above-mentioned problems concerning the storage capacity, calculation error, and the like have not been examined, either.

Furthermore, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 57-4018, 58-137812, 58-137814, 58-144808, 58-149014, 58-150925, and the like, each of which utilizes only a focus cam, the problems of the storage capacity, calculation error, and the like have not been examined, either.

On the other hand, as in Japanese Patent Application Laid-Open Nos. 63-163808, 1-154014, and the like, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 64-35515, 64-35516, 4-140704, and the like, each of which commonly uses a single cam as both a focus cam and a zoom cam, the above-mentioned problems of the storage capacity, calculation error, and the like have not been examined, either. In addition, the zoom lens disclosed in these references has a basic structure different from that of the present invention since it does not require any zoom compensation cam, and does not take a so-called flexible manual focusing operation into account, which has been examined in Japanese Patent Application Laid-Open Nos. 4-293008, 5-142475, and the like.

A zoom lens disclosed in Japanese Patent Application Laid-open Nos. 2-256011 and 3-101707 which have been assigned to the same assignee as the present invention, and Japanese Patent Application Laid-Open No. 7-120662 which discloses a technical content similar to those disclosed in the above Japanese Patent Application Laid-Open Nos. 2-256011 and 3-101707, has a basic structure different from that of the present invention since it realizes zooming by a relative movement, in the direction of rotation of a lens barrel, between a focus cam and a zoom cam, and focusing by a relative movement in the direction of the optical axis, and does not examine an auto-focusing operation at all.

Similarly, in Japanese Patent Application Laid-Open No. 7-5362, a zoom lens disclosed therein has a basic structure different from that of the present invention since the amount of movement for focusing is to be defined by synthesizing two kinds of cams without using a focus cam directly, and the above-mentioned problems concerning the storage capacity, calculation error, and the like have not been examined.

Furthermore, Japanese Patent Application Laid-Open Nos. 61-77027, 1-232313, and the like disclose a lens system having a focus cam so as to realize an accurate auto-focusing operation with a small calculation error. However, these references relate to a single-focus lens having no zooming function, and cannot be applied to a focus cam required to achieve a so-called manual focusing operation in a zoom lens in which the amount of movement in the direction of the optical axis for focusing changes depending on the zooming state.

The principle of the auto-focus operation will be briefly described below.

An auto-focusing system disclosed in Japanese Patent Application Laid-Open Nos. 62-78519, 62-170924, 1-131507, 1-131508, 1-131509, 3-228006, and the like, comprises focus detection means, calculation means for calculating the lens driving amount for focusing, and storage means for storing specific constants used in calculations. In this system, the focus detection means detects the defocus amount ΔBf between the imaging position of an actual object by the photographing optical system and a predetermined imaging point position, and the calculation means for calculating the lens driving amount for focusing calculates the lens driving amount Δx for focusing on the basis of the detected defocus amount ΔBf of the photographing optical system, thus achieving an auto-focusing operation.

If the relationship between the lens driving amount Δx for focusing and the defocus amount ΔBf is expressed using a conversion coefficient K associated with focusing as follows:

    Δx=ΔBf/K

then, the lens driving amount Δx can be calculated by setting the conversion coefficient K.

However, as described in Japanese Patent Application Laid-Open No. 62-170924, the conversion coefficient K changes in correspondence not only with the focal length but also with the object position and lens arrangement.

Therefore, as described in Japanese Patent Application Laid-Open Nos. 62-78519, 62-170924, and the like, using the conversion coefficient γ defined as the ratio (sensitivity) of the amount of infinitesimal movement of the imaging plane with respect to the amount of infinitesimal movement of the focusing lens unit in the vicinity of a predetermined in-focus point, and the correction coefficient ε for correcting the conversion coefficient in accordance with the defocus amount ΔBf, the conversion coefficient K is calculated by the following formulas:

    K=γ+ε·f(ΔBf)

    K=γ+ε·ΔBf.sup.2 in Japanese Patent Application Laid-Open No. 62-78519

    K=γ(1+ε·ΔBf) in Japanese Patent Application Laid-Open No. 62-170924

and thereafter, the lens driving amount Δx is calculated based on the conversion coefficient K. (Of course, the lens driving amount Δx for focusing may be directly calculated from the defocus amount ΔBf using the conversion coefficient γ and the correction coefficient ε.)

Furthermore, in a photographing system having a zooming optical system, since the values of the conversion coefficient γ and the correction coefficient ε change depending on the lens arrangement, a plurality of pairs of data of the conversion coefficient γ and the correction coefficient ε are stored in the storage means in units of a plurality of divided zoom ranges and focus ranges, as described in Japanese Patent Application Laid-Open No. 3-228006.

In other words, in the photographing system having the zooming optical system, the focus detection means detects the defocus amount ΔBf caused by the zooming optical system, and values of the conversion coefficient γ and the correction coefficient ε corresponding to the zoom and focus positions respectively detected by zoom and focus position detection means are read out from the storage means. The calculation means for calculating the lens driving amount for focusing calculates the lens driving amount Δx for focusing using the defocus amount ΔBf, the conversion coefficient γ, and the correction coefficient ε, and driving means drives a lens by the calculated lens driving amount Δx for focusing, thus achieving a focusing operation.

However, in a normal focusing mechanism using a helicoid mechanism or a cam mechanism, the lens driving amount for focusing must be described not as a lens driving amount Δx in the direction of the optical axis but as a lens driving amount Δa in the direction of rotation.

Therefore, when the relationship between the lens driving amount Δx and the defocus amount ΔBf in the direction of the optical axis is converted into the relationship between the lens driving amount Δa and the defocus amount ΔBf in the direction of rotation using a conversion coefficient K_(a) associated with the direction of rotation, we have:

    Δa=ΔBf/K.sub.a

If conversion coefficient K associated with the direction of the optical axis is newly defined as K_(x), the conversion coefficient K_(a) associated with the direction of rotation is expressed using a conversion coefficient Φ between the lens driving amount Δx in the direction of the optical axis and the lens driving amount Δa in the direction of rotation as follows:

    K.sub.a =K.sub.x ·Φ

Thus, the formula in Japanese Patent Application Laid-Open No. 62-170924 is modified to a formula associated with the conversion coefficient K_(a) in the direction of rotation as follows:

    K.sub.a =Φγ(1+ε·ΔBf)

If Δx and Δa have a linear relationship therebetween like in a helicoid mechanism, Φ becomes a constant. However, when a cam mechanism is used, the conversion coefficient Φ changes depending on the cam shape. The conversion coefficient Φ can be replaced by a slope (dx/da) defined by the cam shape as follows:

    K.sub.a =γ·(dx/da)(1+ε·ΔBf)

The conversion coefficient γ and the correction coefficient ε in an inner focusing type zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 4-293008, 5-142475, and the like will be examined below.

When a zoom lens system is constituted by n lens units, and its k-th lens unit is used as the focusing lens unit, if the ratio of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement, in the direction of the optical axis, of the focusing lens unit, i.e., the conversion coefficient γ (dBf/dx: the sensitivity associated with movement in the direction of the optical axis) is defined as a new conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis, the conversion coefficient γ_(x) can be expressed using the imaging magnifications β of the respective lens units as follows:

    γ.sub.x =(1-β.sub.k.sup.2)β.sub.k+1.sup.2 β.sub.k+2.sup.2 . . . β.sub.n.sup.2

Therefore, the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis can be expressed using the imaging magnifications β_(Ok) and β_(Rk) of the focusing lens unit at the infinity and closest in-focus points as follows:

    γ.sub.xR /γ.sub.xO =(1-β.sub.Rk.sup.2)/(1-β.sub.Ok.sup.2)

Furthermore, if the ratio of the amount dBf of infinitesimal movement of the imaging plane to the angle da of infinitesimal rotation of the focusing lens unit (dBf/da: the sensitivity associated with movement in the direction of rotation) is defined as a new conversion coefficient γ_(a) associated with the angle a of rotation of a rotatable lens barrel, the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel can be expressed by:

    γ.sub.a =γ.sub.x ·(dx/da)

where dx/da is the slope of the focus cam.

Therefore, the rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel can be expressed using slopes (dx/da)_(O) and (dx/da)_(R) at the infinity and closest corresponding positions on the focus cam as follows:

    γ.sub.aR /γ.sub.aO =(γ.sub.xR /γ.sub.xO)·((dx/da).sub.R /(dx/da).sub.O)

The rate of change of the conversion coefficient γ_(x) with respect to the amount x of movement in the direction of the optical axis and the rate of change of the conversion coefficient γ_(a) with respect to the angle a of rotation of the rotatable lens barrel will be examined below in association with a case in which the amount of rotation corresponding to the zooming from the wide-angle end to the telephoto end and the ratio of amounts of rotation (a_(F) /a_(Z)) with respect to the focusing from the infinity in-focus state to the closest in-focus state are set to be 1.0 in the first embodiment of the present invention, like in an embodiment of Japanese Patent Application Laid-Open No. 5-142475 mentioned above. Note that the amount of rotation for zooming from the wide-angle end to the telephoto end and the amount of rotation for focusing are respectively re-set to be 10.0 for the purpose of a comparison with an embodiment of the present invention.

Table 1 below summarizes various paraxial data of an optical system and data for defining the shape of the focus cam in a case in which the ratio of the amounts of rotation (a_(F) /a_(Z)) is to set to be 1.0 in the first embodiment of the present invention, like in the embodiment of Japanese Patent Application Laid-Open No. 5-142475. (Said case will be hereinafter called the comparative example I).

The upper table in Table 1 summarizes the focal length data and principal point interval data of the respective lens units of the optical system corresponding to the comparative example I. In this table, F1, F2, F3, and F4 are respectively the focal lengths of first, second, third and fourth lens units, and D1, D2, D3, and D4 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, and the principal point interval between the fourth lens unit and a predetermined imaging plane in six zooming states (focal lengths F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 85.0 (4-POS), 135.0 (5-POS), and 194.0 mm (6-POS)).

The middle table in Table 1 summarizes spline sample point data when the shape of the focus cam in the second lens unit which is used for focusing is expressed by a spline function associated with the angle a of rotation of the rotatable lens barrel and the amount x of movement in the direction of the optical axis (complying with "Numerical Analysis and FORTRAN", MARUZEN, "Spline Function and Its Applications", Kyoiku Shuppan, and the like). In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 1 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=28.8, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) using the focus cam. Since both the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=194.0) and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.95 m) are 10.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming is 1.0.

                                      TABLE 1                                      __________________________________________________________________________     F = 28.0-194.0 (Rotation Amount Ratio: a.sub.F /a.sub.z                        __________________________________________________________________________     = 1.0)                                                                         Focal lengths and Principal Point Intervals of Lens Units of Comparative       Example I                                                                               1-POS                                                                              2-POS                                                                              3-POS                                                                              4-POS                                                                               5-POS                                                                               6-POS                                           __________________________________________________________________________            F 28.8000                                                                            35.0000                                                                            50.0000                                                                            85.0000                                                                             135.0000                                                                            194.0000                                        F1                                                                               85.0000                                                                             D1                                                                               11.5063                                                                            15.6399                                                                            23.6055                                                                            35.1974                                                                             44.4737                                                                             50.4202                                         F2                                                                               -14.7000                                                                            D2                                                                               25.8069                                                                            23.2088                                                                            19.3898                                                                            14.8844                                                                             11.1724                                                                             7.8560                                          F3                                                                               43.5000                                                                             D3                                                                               8.0000                                                                             7.3138                                                                             5.7748                                                                             3.8464                                                                              2.8540                                                                              2.0039                                          F4                                                                               61.0000                                                                             D4                                                                               59.7035                                                                            64.5166                                                                            73.5311                                                                            86.9840                                                                             97.2356                                                                             104.6041                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) of                         Comparative Example I                                                             ANGLE    (1)                                                                               (2)       (3)                                                                               (4)                                                __________________________________________________________________________     1  .0000    .0000                                                                             .0000     .0000                                                                             .0000                                              2  4.8070   .0000                                                                             .0973     .0000                                                                             .0000                                              3  6.1968   .0000                                                                             .1633     .0000                                                                             .0000                                              4  7.4292   .0000                                                                             .2472     .0000                                                                             .0000                                              5  8.3658   .0000                                                                             .3325     .0000                                                                             .0000                                              6  9.1510   .0000                                                                             .4194     .0000                                                                             .0000                                              7  10.0000  .0000                                                                             .5362     .0000                                                                             .0000                                              8  14.8070  .0000                                                                             1.9234    .0000                                                                             .0000                                              9  16.1968  .0000                                                                             2.6178    .0000                                                                             .0000                                              10 17.4292  .0000                                                                             3.3494    .0000                                                                             .0000                                              11 18.3658  .0000                                                                             3.9814    .0000                                                                             .0000                                              12 19.1510  .0000                                                                             4.5444    .0000                                                                             .0000                                              13 20.0000  .0000                                                                             5.2095    .0000                                                                             .0000                                              __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Comparative Example I                                                          Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.0)                                 __________________________________________________________________________                    Infinity        Amount of                                                      Correspond-                                                                          Photograph-                                                                              Rotation for                                    Focal Length   ing Position                                                                         ing Distance                                                                             Focusing                                        __________________________________________________________________________     28.8 mm        .0000  5.00 m   4.807                                           35.0 mm        .5467  3.00 m   6.197                                           50.0 mm        1.7264                                                                                2.00 m   7.429                                           85.0 mm        4.0063                                                                                1.50 m   8.366                                           135.0 mm       6.8742                                                                                1.20 m   9.151                                           194.0 mm       10.0000                                                                               0.95 m   10.000                                          Condition Corresponding Value (1)                                                                    1.81                                                     Condition Corresponding Value (2)                                                                    8.72                                                     Condition Corresponding Value (3)                                                                    1.00                                                     Condition Corresponding Value (4)                                                                   14.32 (wide-angle end)                                                          9.37 (telephoto end)                                     Condition Corresponding Value (5)                                                                    5.05 (wide-angte end)                                                          9.49 (telephoto end)                                     Condition Corresponding Value (6)                                                                    0.33 (wide-angle end)                                                          0.30 (telephoto end)                                     __________________________________________________________________________

Table 2 below summarizes the numerical value data of the cams of the focusing lens unit in the comparative example I, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 1. In this table, (ANGLE) is the angle of rotation of the rotatable lens barrel, (2) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 2                                                          ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Comparative                  Example I                                                                                       Zoom Compensation Cam Numerical                               Focus Cam Numerical Value Data                                                                  Value Data                                                    ANGLE (2)       F        ANGLE  (2)   F                                        ______________________________________                                         .0000 .0000     28.8000  .0000  .0000 28.8000                                  .5000 .0056     34.4507  .5000  1.3899                                                                               34.4507                                  1.0000                                                                               .0114     40.4957  1.0000 2.8644                                                                               40.4957                                  1.5000                                                                               .0179     46.9366  1.5000 4.4323                                                                               46.9366                                  2.0000                                                                               .0252     53.8335  2.0000 6.0605                                                                               53.8335                                  2.5000                                                                               .0338     61.1687  2.5000 7.6964                                                                               61.1687                                  3.0000                                                                               .0438     68.8474  3.0000 9.2783                                                                               68.8474                                  3.5000                                                                               .0557     76.7811  3.5000 10.7612                                                                              76.7811                                  4.0000                                                                               .0696     84.8965  4.0000 12.1183                                                                              84.8965                                  4.5000                                                                               .0860     93.1568  4.5000 13.3400                                                                              93.1568                                  5.0000                                                                               .1050     101.6074 5.0000 14.4342                                                                              101.6074                                 5.5000                                                                               .1271     110.2708 5.5000 15.4096                                                                              110.2708                                 6.0000                                                                               .1524     119.1222 6.0000 16.2732                                                                              119.1222                                 6.5000                                                                               .1814     128.1362 6.5000 17.0347                                                                              128.1362                                 7.0000                                                                               .2146     137.3353 7.0000 17.7078                                                                              137.3353                                 7.5000                                                                               .2529     146.7582 7.5000 18.3072                                                                              146.7582                                 8.0000                                                                               .2969     156.3343 8.0000 18.8416                                                                              156.3343                                 8.5000                                                                               .3462     165.8058 8.5000 19.3089                                                                              165.8058                                 9.0000                                                                               .4013     175.1330 9.0000 19.7185                                                                              175.1330                                 9.5000                                                                               .4641     184.6090 9.5000 20.0905                                                                              184.6090                                 10.0000                                                                              .5362     194.0000 10.0000                                                                               20.4174                                                                              194.0000                                 10.5000                                                                              .6194     .0000                                                          11.0000                                                                              .7146     .0000                                                          11.5000                                                                              .8227     .0000                                                          12.0000                                                                              .9446     .0000                                                          12.5000                                                                              1.0810    .0000                                                          13.0000                                                                              1.2328    .0000                                                          13.5000                                                                              1.4009    .0000                                                          14.0000                                                                              1.5861    .0000                                                          14.5000                                                                              1.7894    .0000                                                          15.0000                                                                              2.0114    .0000                                                          15.5000                                                                              2.2523    .0000                                                          16.0000                                                                              2.5112    .0000                                                          16.5000                                                                              2.7872    .0000                                                          17.0000                                                                              3.0811    .0000                                                          17.5000                                                                              3.3952    .0000                                                          18.0000                                                                              3.7290    .0000                                                          18.5000                                                                              4.0750    .0000                                                          19.0000                                                                              4.4323    .0000                                                          19.5000                                                                              4.8124    .0000                                                          20.0000                                                                              5.2095    .0000                                                          ______________________________________                                    

The left table in Table 2 summarizes the numerical value data of the focus cam in the comparative example I, and the right table in Table 2 summarizes the numerical value data of the zoom compensation cam of the comparative example I. A value obtained by synthesizing the amount (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the amount (2) of movement in the direction of the optical axis in the numerical value data of the zoom compensation cam in a range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) agrees with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 1.

Tables 3, 4, and 5 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(k) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=85.0), and the telephoto end (F=194.0), respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), and 4) on the right side respectively represent the first, second, third, and fourth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(k) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m).

                                      TABLE 3                                      __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End (28.8 mm) in Comparative Example 1                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               3.203                                                                              1)                                                                               .000                                                                               2)                                                                               .048                                                                               3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               .097                                                                               3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               .163                                                                               3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               .247                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               .332                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               .419                                                                               3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .536                                                                               3)                                                                               .000 4)                                                                               .000                                         Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in                                                                         Comparative Example I                                                          R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.250                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 10.000                                                                             ANG                                                                               3.203                                                                              1)                                                                               -.009                                                                              2)                                                                               -.247                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               -.018                                                                              2)                                                                               -.243                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               -.030                                                                              2)                                                                               -.239                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               -.047                                                                              2)                                                                               -.233                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               -.065                                                                              2)                                                                               -.227                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               -.084                                                                              2)                                                                               -.221                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.112                                                                              2)                                                                               -.214                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle                                                             End (28.8 mm) in Comparative Example I                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.722                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               3.203                                                                              1)                                                                               .000                                                                               2)                                                                               1.725                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               1.728                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               1.732                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               1.737                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               1.741                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               1.746                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.753                                                                              3)                                                                               .000 4)                                                                               .000                                         Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in Comparative            Example I                                                                      R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .011                                                                               3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               3.203                                                                              1)                                                                               .000                                                                               2)                                                                               .023                                                                               3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               .039                                                                               3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               .057                                                                               3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               .081                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               .101                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               .122                                                                               3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .155                                                                               3)                                                                               .000 4)                                                                               .000                                         Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (28.8 mm) in Comparative Example I                                             R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .019                                                                               3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               3.203                                                                              1)                                                                               .000                                                                               2)                                                                               .040                                                                               3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               .067                                                                               3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               .099                                                                               3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               .140                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               .176                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               .213                                                                               3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .272                                                                               3)                                                                               .000 4)                                                                               .000                                         __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.02,         γ.sub.aR /γ.sub.a0 = 14.32                                   

                                      TABLE 4                                      __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (85.0 mm) in Comparative Example I                                    R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.101                                                                              1)                                                                               .000                                                                               2)                                                                               .152                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.741                                                                              1)                                                                               .000                                                                               2)                                                                               .303                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.206                                                                              1)                                                                               .000                                                                               2)                                                                               .500                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.448                                                                              1)                                                                               .000                                                                               2)                                                                               .743                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.387                                                                              1)                                                                               .000                                                                               2)                                                                               .981                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.154                                                                              1)                                                                               .000                                                                               2)                                                                               1.215                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.519                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Middle Position (85.0      mm) in                                                                         Comparative Example I                                                          R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.419                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 10.000                                                                             ANG                                                                               3.101                                                                              1)                                                                               -.009                                                                              2)                                                                               -.408                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 5.000                                                                              ANG                                                                               4.741                                                                              1)                                                                               -.018                                                                              2)                                                                               -.398                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 3.000                                                                              ANG                                                                               6.206                                                                              1)                                                                               -.031                                                                              2)                                                                               -.385                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 2.000                                                                              ANG                                                                               7.448                                                                              1)                                                                               -.048                                                                              2)                                                                               -.368                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 1.500                                                                              ANG                                                                               8.387                                                                              1)                                                                               -.067                                                                              2)                                                                               -.352                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 1.200                                                                              ANG                                                                               9.154                                                                              1)                                                                               -.087                                                                              2)                                                                               -.336                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.117                                                                              2)                                                                               -.315                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle                                                                 Position (85.0 mm) in Comparative Example I                                    R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               4.702                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.101                                                                              1)                                                                               .000                                                                               2)                                                                               4.751                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.741                                                                              1)                                                                               .000                                                                               2)                                                                               4.798                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.206                                                                              1)                                                                               .000                                                                               2)                                                                               4.858                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.448                                                                              1)                                                                               .000                                                                               2)                                                                               4.929                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.387                                                                              1)                                                                               .000                                                                               2)                                                                               4.995                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.154                                                                              1)                                                                               .000                                                                               2)                                                                               5.058                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               5.135                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Middle Position (85.0 mm) in Comparative           Example I                                                                      R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .030                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.101                                                                              1)                                                                               .000                                                                               2)                                                                               .073                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.741                                                                              1)                                                                               .000                                                                               2)                                                                               .110                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.206                                                                              1)                                                                               .000                                                                               2)                                                                               .165                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.448                                                                              1)                                                                               .000                                                                               2)                                                                               .227                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.387                                                                              1)                                                                               .000                                                                               2)                                                                               .281                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.154                                                                              1)                                                                               .000                                                                               2)                                                                               .330                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .389                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle                                                             Position (85.0 mm) in Comparative Example I                                    R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .142                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.101                                                                              1)                                                                               .000                                                                               2)                                                                               .349                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.741                                                                              1)                                                                               .000                                                                               2)                                                                               .528                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.206                                                                              1)                                                                               .000                                                                               2)                                                                               .799                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.448                                                                              1)                                                                               .000                                                                               2)                                                                               1.120                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.387                                                                              1)                                                                               .000                                                                               2)                                                                               1.406                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.154                                                                              1)                                                                               .000                                                                               2)                                                                               1.670                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.996                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.09,         γ.sub.aR /γ.sub.a0 = 14.06                                   

                                      TABLE 5                                      __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End (194.0 mm) in Comparative Example I                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.212                                                                              1)                                                                               .000                                                                               2)                                                                               .766                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               1.387                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               2.082                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               2.813                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               3.445                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               4.008                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               4.673                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Telephoto End (194.0       mm) in                                                                         Comparative Example I                                                          R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.739                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 10.000                                                                             ANG                                                                               3.212                                                                              1)                                                                               -.009                                                                              2)                                                                               -.687                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               -.018                                                                              2)                                                                               -.645                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               -.031                                                                              2)                                                                               -.598                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               -.049                                                                              2)                                                                               -.548                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               -.068                                                                              2)                                                                               -.505                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               -.089                                                                              2)                                                                               -.467                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.121                                                                              2)                                                                               -.422                                                                              3)                                                                               4.318                                                                              4)                                                                               -.715                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto                                                              End (194.0 mm) in Comparative Example I                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               4.318                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.212                                                                              1)                                                                               .000                                                                               2)                                                                               5.026                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               5.563                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               6.122                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               6.665                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               7.097                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               7.451                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               7.834                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Telephoto End (194.0 mm) in Comparative            Example I                                                                      R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .155                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.212                                                                              1)                                                                               .000                                                                               2)                                                                               .334                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               .448                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               .548                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               .644                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               .696                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .000                                                                               2)                                                                               .750                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .800                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (194.0 mm) in Comparative Example I                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .669                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               3.212                                                                              1)                                                                               .000                                                                               2)                                                                               1.677                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               4.807                                                                              1)                                                                               .000                                                                               2)                                                                               2.495                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               6.197                                                                              1)                                                                               .000                                                                               2)                                                                               3.356                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               7.429                                                                              1)                                                                               .000                                                                               2)                                                                               4.290                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               8.366                                                                              1)                                                                               .000                                                                               2)                                                                               4.938                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               9.151                                                                              1)                                                                               .006                                                                               2)                                                                               5.592                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               6.267                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.81,         γ.sub.aR /γ.sub.a0 = 9.37                                    

As can be seen from Tables 3, 4, and 5, the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope (dx/da) of the focus cam at the respective focal lengths increase as the photographing distance becomes closer to the closest distance. Especially, the slope (dx/da) of the focus cam changes largely. Therefore, as can be seen from these tables, the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of γ_(x) and (dx/da), further increases.

More specifically, in a zoom lens in which the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit in a closest in-focus state is larger than that in an infinity in-focus state, i.e., which satisfies:

    1.0<γ.sub.xR /γ.sub.xO

when the focus cam which satisfies the following inequality, i.e., the focus cam has a shape having a larger slope (dx/da) at the closest corresponding position than that at the infinity corresponding position:

    1.0<<(dx/da).sub.R /(dx/da).sub.O

the following inequality is satisfied:

    1.0<γ.sub.xR /γ.sub.xO <<γ.sub.aR /γ.sub.aO

The rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel undesirably becomes larger than the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis.

From Tables 3, 4, and 5 above, the rate of change of γ_(a) is ×14.32 at the wide-angle end (F=28.8), ×14.06 at the middle position (F=85.0), and ×9.37 at the telephoto end (F=194.0).

As described above, when the conversion coefficient γ changes in correspondence with the lens arrangement (e.g., focusing), as described in Japanese Patent Application Laid-Open No. 3-228006, a plurality of pairs of data of the conversion coefficient γ and the correction coefficient ε must be stored in the storage means in units of a plurality of divided focus ranges. Therefore, when the rate of change of γ_(a) is large (γ_(aR) /γ_(aO) >>1.0), the number of divisions increases, and the storage capacity inevitably becomes large, resulting in an increase in cost. For example, when a change in γ_(a) in a single focus range is divided under the condition defined by the following inequality:

    γ.sub.max /γ.sub.min <1.2

the number N of divisions is expressed by inequality (a) below:

    N>log (γ.sub.MAX /γ.sub.MIN)/log (1.2)         (a)

Therefore, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end have large values as follows:

    N.sub.W >14.6N.sub.M >14.5N.sub.T >12.3

The formula K=γ(1+ε·ΔBf) presented by Japanese Patent Application Laid-Open No. 62-170924 is rewritten to the conversion coefficient K_(a) associated with the angle a of rotation of the rotatable lens barrel:

    K.sub.a =γ.sub.a (1+ε·ΔBf)

Then, the following formula is defined by using a correction coefficient μ (ε=-1/μ):

    K.sub.a =γ.sub.a (1-ΔBf/μ)

Tables 6, 7, and 8 below summarize the calculation results of the values of the conversion coefficient K_(a) and the correction coefficient μ according to the comparative example I at the wide-angle end (F=28.8), middle position (F=85.0), and telephoto end (F=194.0) using the above formula.

In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 mm), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 6, 7, and 8, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and the object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 6, 7, and 8, i.e., in the ninth and 10th columns is (R, ANGLE)=(0.95, 10.0), and it indicates that this position corresponds to the closest in-focus (R=0.95 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=0.95 m) object, and the 10th column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.95 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the 10th column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.95 m) object to an in-focus state at the object distance in the second column.

From the above formulas, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μ is calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eighth row, fourth column in first table: 0.096) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=0.95 m) in Table 6 is calculated by K_(a) =0.96/10.0=0.096 using ΔBf=0.96 and Δa=10.0. On the other hand, the value of the correction coefficient μ (eighth row, fourth column in second table: -0.24) is calculated as μ=-0.24 using ΔBf=0.96, K_(a) =0.096, and Y_(a) =0.019.

                                      TABLE 6                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and                                                 Correction Coefficient μ: (l) at Wide-angle End (28.8 mm) in                Comparative Example I                                                          F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             3.203                                                                              5.000                                                                              4.807                                                                              3.000                                                                              6.197                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .019                                                                               .000    .026    .035    .045                                        2  10.000  .026                                                                               .040                                                                               .000    .052    .066                                        3  5.000   .035    .053                                                                               .067                                                                               .000    .082                                        4  3.000   .046    .067    .082                                                                               .099                                                                               .000                                        5  2.000   .058    .082    .100    .119                                        6  1.500   .070    .097    .116    .137                                        7  1.200   .082    .111    .131    .153                                        8  .950    .096    .129    .151    .175                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               -.24                                                                               -.17                                                                               -.35                                                                               -.28                                                                               -.51                                        2  10.000                                                                             .08 -.22                                                                               .00 .00 -.08                                                                               -.39                                                                               -.20                                                                               -.59                                        3  5.000                                                                              .17 -.20                                                                               .08 -.27                                                                               .00 .00 -.11                                                                               -.66                                        4  3.000                                                                              .28 -.20                                                                               .20 -.30                                                                               .11 -.49                                                                               .00 .00                                         5  2.000                                                                              .43 -.21                                                                               .35 -.33                                                                               .26 -.53                                                                               .15 -.73                                        6  1.500                                                                              .59 -.22                                                                               .50 -.35                                                                               .41 -.56                                                                               .30 -.77                                        7  1.200                                                                              .75 -.23                                                                               .66 -.38                                                                               .57 -.59                                                                               .45 -.82                                        8  .950                                                                               .96 -.24                                                                               .87 -.40                                                                               .79 -.62                                                                               .67 -.86                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              7.429                                                                              1.500                                                                              8.366                                                                              1.200                                                                              9.151                                                                              .950                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .057    .067    .077    .090                                        2  10.000  .080    .094    .106    .121                                        3  5.000   .098    .113    .126    .143                                        4  3.000   .117    .134    .148    .167                                        5  2.000                                                                              .140                                                                               .000    .158    .172    .193                                        6  1.500   .159                                                                               .176                                                                               .000    .192    .215                                        7  1.200   .176    .194                                                                               .213                                                                               .000    .239                                        8  .950    .200    .221    .242                                                                               .272                                                                               .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.42                                                                               -.71                                                                               -.56                                                                               -.91                                                                               -.71                                                                               -1.11                                                                              -.90                                                                               -1.35                                       2  10.000                                                                             -.34                                                                               -.80                                                                               -.48                                                                               -1.03                                                                              -.63                                                                               -1.25                                                                              -.82                                                                               -1.48                                       3  5.000                                                                              -.26                                                                               -.86                                                                               -.40                                                                               -1.12                                                                              -.55                                                                               -1.35                                                                              -.74                                                                               -1.57                                       4  3.000                                                                              -.14                                                                               -.89                                                                               -.29                                                                               -1.22                                                                              -.44                                                                               -1.45                                                                              -.63                                                                               -1.65                                       5  2.000                                                                              .00 .00 -.15                                                                               -1.40                                                                              -.30                                                                               -1.56                                                                              -.50                                                                               -1.70                                       6  1.500                                                                              .15 -1.09                                                                              .00 .00 -.15                                                                               -1.53                                                                              -.35                                                                               -1.69                                       7  1.200                                                                              .30 -1.18                                                                              .15 -1.49                                                                              .00 .00 -.20                                                                               -1.69                                       8  .950                                                                               .51 -1.21                                                                              .36 -1.43                                                                              .21 -1.48                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 5.05, K.sub.aR      /γ.sub.aR = 0.33                                                   

                                      TABLE 7                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (85.0 mm) in Comparative Example      F = 85.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             3.101                                                                              5.000                                                                              4.741                                                                              3.000                                                                              6.206                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .142                                                                               .000    .229    .294    .366                                        2  10.000  .236                                                                               .349                                                                               .000    .431    .519                                        3  5.000   .313    .444                                                                               .527                                                                               .000    .638                                        4  3.000   .406    .558    .664                                                                               .800                                                                               .000                                        5  2.000   .520    .700    .828    .979                                        6  1.500   .631    .835    .979    1.142                                       7  1.200   .741    .967    1.125   1.298                                       8  .950    .886    1.140   1.314   1.499                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.71                                                                               -2.06                                                                              -1.39                                                                              -3.16                                                                              -2.27                                                                              -4.20                                       2  10.000                                                                             .73 -1.11                                                                              .00 .00 -.71                                                                               -3.86                                                                              -1.61                                                                              -4.60                                       3  5.000                                                                              1.49                                                                               -1.24                                                                              .73 -2.67                                                                              .00 .00 -.93                                                                               -4.61                                       4  3.000                                                                              2.52                                                                               -1.36                                                                              1.73                                                                               -2.90                                                                              .97 -3.75                                                                              .00 .00                                         5  2.000                                                                              3.87                                                                               -1.46                                                                              3.04                                                                               -3.03                                                                              2.24                                                                               -3.94                                                                              1.22                                                                               -5.44                                       6  1.500                                                                              5.29                                                                               -1.54                                                                              4.41                                                                               -3.17                                                                              3.57                                                                               -4.17                                                                              2.49                                                                               -5.82                                       7  1.200                                                                              6.78                                                                               -1.61                                                                              5.86                                                                               -3.31                                                                              4.96                                                                               -4.38                                                                              3.83                                                                               -6.14                                       8  .950                                                                               8.86                                                                               -1.69                                                                              7.87                                                                               -3.47                                                                              6.91                                                                               -4.63                                                                              5.69                                                                               -6.51                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              7.448                                                                              1.500                                                                              8.387                                                                              1.200                                                                              9.154                                                                              .950                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .446    .515    .576    .646                                        2  10.000  .619    .704    .776    .859                                        3  5.000   .756    .851    .931    1.021                                       4  3.000   .931    1.034   1.120   1.214                                       5  2.000                                                                              1.120                                                                              .000    1.229   1.319   1.418                                       6  1.500   1.291                                                                              1.407                                                                              .000    1.499   1.601                                       7  1.200   1.454   1.574                                                                              1.669                                                                              .000    1.774                                       8  .950    1.664   1.789   1.889                                                                              1.994                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -3.32                                                                              -5.52                                                                              -4.32                                                                              -6.82                                                                              -5.27                                                                              -8.05                                                                              -6.46                                                                              -9.57                                       2  10.000                                                                             -2.69                                                                              -6.02                                                                              -3.72                                                                              -7.44                                                                              -4.70                                                                              -8.78                                                                              -5.92                                                                              -10.40                                      3  5.000                                                                              -2.05                                                                              -6.28                                                                              -3.10                                                                              -7.85                                                                              -4.11                                                                              -9.30                                                                              -5.37                                                                              -11.00                                      4  3.000                                                                              -1.16                                                                              -6.84                                                                              -2.26                                                                              -8.51                                                                              -3.30                                                                              -10.03                                                                             -4.61                                                                              -11.78                                      5  2.000                                                                              .00 .00 -1.15                                                                              -9.14                                                                              -2.25                                                                              -10.73                                                                             -3.62                                                                              -12.51                                      6  1.500                                                                              1.21                                                                               -7.96                                                                              .00 .00 -1.15                                                                              -11.31                                                                             -2.58                                                                              -13.09                                      7  1.200                                                                              2.48                                                                               -8.32                                                                              1.21                                                                               -10.17                                                                             .00 .00 -1.50                                                                              -13.60                                      8  .950                                                                               4.25                                                                               -8.75                                                                              2.89                                                                               -10.62                                                                             1.60                                                                               -12.13                                                                             .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 6.24, K.sub.aR      /γ.sub.aR = 0.32                                                   

                                      TABLE 8                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (#) at Telephoto End (194.0 mm) in Comparative Example       F = 194.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             3.212                                                                              5.000                                                                              4.807                                                                              3.000                                                                              6.197                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .669                                                                               .000    1.031   1.244   1.436                                       2  10.000  1.215                                                                              1.676                                                                              .000    1.930   2.144                                       3  5.000   1.686   2.218                                                                              2.493                                                                              .000    2.704                                       4  3.000   2.298   2.897   3.175                                                                              3.354                                                                              .000                                        5  2.000   3.084   3.736   4.002   4.160                                       6  1.500   3.937   4.623   4.862   4.979                                       7  1.200   4.881   5.567   5.752   5.793                                       8  .950    6.351   6.992   7.074   6.992                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -3.31                                                                              -8.60                                                                              -5.98                                                                              -11.93                                                                             -8.90                                                                              -15.57                                      2  10.000                                                                             3.90                                                                               -4.79                                                                              .00 .00 -3.08                                                                              -13.65                                                                             -6.40                                                                              -17.74                                      3  5.000                                                                              8.11                                                                               -5.34                                                                              3.54                                                                               -10.95                                                                             .00 .00 -3.76                                                                              -19.40                                      4  3.000                                                                              14.24                                                                              -5.85                                                                              8.65                                                                               -11.88                                                                             4.41                                                                               -16.11                                                                             .00 .00                                         5  2.000                                                                              22.91                                                                              -6.35                                                                              15.76                                                                              -12.82                                                                             10.49                                                                              -17.33                                                                             5.13                                                                               -21.34                                      6  1.500                                                                              32.94                                                                              -6.75                                                                              23.83                                                                              -13.55                                                                             17.30                                                                              -18.20                                                                             10.80                                                                              -22.29                                      7  1.200                                                                              44.67                                                                              -7.10                                                                              33.06                                                                              -14.25                                                                             24.99                                                                              -19.11                                                                             17.11                                                                              -23.54                                      8  .950                                                                               63.51                                                                              -7.48                                                                              47.46                                                                              -14.97                                                                             36.73                                                                              -19.99                                                                             26.59                                                                              -24.52                                      __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              7.429                                                                              1.500                                                                              8.366                                                                              1.200                                                                              9.151                                                                              .950                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    1.600   1.718   1.804   1.893                                       2  10.000  2.310   2.424   2.498   2.574                                       3  5.000   2.856   2.958   3.013   3.071                                       4  3.000   3.493   3.577   3.601   3.633                                       5  2.000                                                                              4.289                                                                              .000    4.313   4.277   4.275                                       6  1.500   5.033                                                                              4.934                                                                              .000    4.876   4.869                                       7  1.200   5.748   5.608                                                                              5.589                                                                              .000    5.227                                       8  .950    6.830   6.633   6.536                                                                              6.260                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -11.89                                                                             -18.96                                                                             -14.37                                                                             -22.05                                                                             -16.51                                                                             -24.38                                                                             -18.93                                                                             -27.14                                      2  10.000                                                                             -9.74                                                                              -21.12                                                                             -12.49                                                                             -24.56                                                                             -14.83                                                                             -26.83                                                                             -17.47                                                                             -29.66                                      3  5.000                                                                              -7.49                                                                              -22.43                                                                             -10.53                                                                             -26.29                                                                             -13.09                                                                             -28.40                                                                             -15.95                                                                             -31.30                                      4  3.000                                                                              -4.31                                                                              -23.22                                                                             -7.76                                                                              -28.21                                                                             -10.64                                                                             -29.91                                                                             -13.82                                                                             -32.93                                      5  2.000                                                                              .00 .00 -4.04                                                                              -32.10                                                                             -7.36                                                                              -31.37                                                                             -10.99                                                                             -34.66                                      6  1.500                                                                              4.71                                                                               -27.17                                                                             .00 .00 -3.83                                                                              -30.02                                                                             -7.96                                                                              -35.79                                      7  1.200                                                                              9.90                                                                               -29.09                                                                             4.40                                                                               -32.20                                                                             .00 .00 -4.69                                                                              -40.03                                      8  .950                                                                               17.56                                                                              -29.64                                                                             10.84                                                                              -31.46                                                                             5.55                                                                               -32.72                                                                             .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 9.49, K.sub.aR      /γ.sub.aR = 0.30                                                   

As can be seen from Tables 6, 7, and 8 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) and a change in correction coefficient μ: (l) (e.g., the fourth column in the second table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) are considered, the conversion coefficient K_(a) and the correction coefficient μ considerably change depending on the object positions. In particular, the conversion coefficient K_(a) has a larger value at the closest object side than that at the infinity object side. Since the conversion coefficient K_(a) in the direction of rotation is defined by K_(a) =ΔBf/Δa, the amount Δa of rotation for focusing at the infinity object side becomes larger than that at the closest object side relative to the defocus amount ΔBf.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end (F=28.8), middle position (F=85.0), and telephoto end (F=194.0) in the comparative example I are as follows.

    ______________________________________                                         Comparative Example I                                                                   Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            5.05           0.33                                                 (F = 28.8)                                                                     Middle Position                                                                           6.24           0.32                                                 (F = 85.0)                                                                     Telephoto End                                                                             9.49           0.30                                                 (F = 194.0)                                                                    ______________________________________                                    

As described above, in the comparative example I, since the change in conversion coefficient K_(a) is large, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) becomes large, and the value of the correction coefficient μ becomes close to that of the defocus amount ΔBf. In addition, the value of the correction coefficient μ largely changes depending on the object positions.

Therefore, as described in Japanese Patent Application Laid-Open No. 3-228006, under the condition that only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range (e.g., an infinity in-focus arrangement range), if the correction coefficient μ which changes largely is represented by only one value, a large error is included in the value of the conversion coefficient K_(a) which is calculated from the conversion coefficient γ_(a) and the correction coefficient μ. Therefore, when the lens driving amount Δa for focusing is finally calculated from the defocus amount ΔBf using the conversion coefficient K_(a), the lens driving amount includes an error, and an auto-focus operation cannot be accurately performed.

For example, upon calculation of the lens driving amount Δa for focusing with respect to a closest distance (R=0.95 m) object when the correction coefficient μ (which changes from -4.79 to -7.48 depending on the object distances) at the infinity in-focus arrangement at the telephoto end (F=194.0) is represented by the value (μ=-6.35) at the middle object distance (R=2.0 m), the lens driving amount Δa for focusing is calculated as Δa=8.63 by substituting ΔBf=63.51, γ_(a) =0.669, and μ=-6.35. The actual lens driving amount for focusing from the state of the infinity in-focus arrangement at the telephoto end (F=194.0) to the closest distance (R=0.95 m) object is Δa=10.0 from (R, ANGLE)=(0.95, 10.0) in the upper right portion of the third table in Table 8. Therefore, an error as large as -13.7% is produced between the actual value and the calculated value Δa=8.74 of the lens driving amount for focusing.

Similarly, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following large values are obtained.

    ______________________________________                                         Comparative Example I                                                                   Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -9.3%         -27.2%                                               (F = 28.8)                                                                     Middle Position                                                                           -11.7%         -28.3%                                               (F = 85.0)                                                                     Telephoto End                                                                             -13.7%         -28.9%                                               (F = 194.0)                                                                    ______________________________________                                    

Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (R=2.0 m), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (R=3.0 m).

Finally, Table 9 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 1) of the comparative example I, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and a displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 9 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and the photographing distances. In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, and fourth lens units in turn from the right side (movement toward the object side is represented by a positive value).

                                      TABLE 9                                      __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Comparative Example I                         __________________________________________________________________________              0.95 m                                                                             1.20 m                                                                              1.50 m                                                                             2.00 m                                                                              3.00 m                                                                             5.00 m                                          __________________________________________________________________________     F 28.800 Bf                                                                             .000                                                                               .000 .000                                                                               .000 .000                                                                               .000                                            F 35.000 Bf                                                                             .000                                                                               .004 .003                                                                               -.002                                                                               -.001                                                                              -.001                                           F 50.000 Bf                                                                             .000                                                                               .014 .023                                                                               .007 -.007                                                                              -.009                                           F 85.000 Bf                                                                             .000                                                                               .005 .029                                                                               .021 .007                                                                               -.035                                           F 135.000 Bf                                                                            .000                                                                               -.068                                                                               -.044                                                                              -.067                                                                               -.072                                                                              -.069                                           F 194.000 Bf                                                                            .000                                                                               .000 .000                                                                               .000 .000                                                                               .000                                            __________________________________________________________________________        ANGLE DA                                                                             10.000                                                                              9.151                                                                              8.366                                                                              7.429 6.197                                                                              4.807                                          __________________________________________________________________________     F  28.800 DX                                                                            .000 .536                                                                               .000                                                                               .000                                                                              R  0.95 m                                             F  35.000 DX                                                                            .000 .622                                                                               .000                                                                               .000                                                                              R  0.95 m                                             F  50.000 DX                                                                            .000 .855                                                                               .000                                                                               .000                                                                              R  0.95 m                                             F  85.000 DX                                                                            .000 1.519                                                                              .000                                                                               .000                                                                              R  0.95 m                                             F  135.000 DX                                                                           .000 2.800                                                                              .000                                                                               .000                                                                              R  0.95 m                                             F  194.000 DX                                                                           .000 4.673                                                                              .000                                                                               .000                                                                              R  0.95 m                                             F  28.800 DX                                                                            .000 .419                                                                               .000                                                                               .000                                                                              R  1.20 m                                             F  35.000 DX                                                                            .000 .485                                                                               .000                                                                               .000                                                                              R  1.20 m                                             F  50.000 DX                                                                            .000 .669                                                                               .000                                                                               .000                                                                              R  1.20 m                                             F  85.000 DX                                                                            .000 1.214                                                                              .000                                                                               .000                                                                              R  1.20 m                                             F  135.000 DX                                                                           .000 2.319                                                                              .000                                                                               .000                                                                              R  1.20 m                                             F  194.000 DX                                                                           .000 4.008                                                                              .000                                                                               .000                                                                              R  1.20 m                                             F  28.800 DX                                                                            .000 .332                                                                               .000                                                                               .000                                                                              R  1.50 m                                             F  35.000 DX                                                                            .000 .385                                                                               .000                                                                               .000                                                                              R  1.50 m                                             F  50.000 DX                                                                            .000 .530                                                                               .000                                                                               .000                                                                              R  1.50 m                                             F  85.000 DX                                                                            .000 .975                                                                               .000                                                                               .000                                                                              R  1.50 m                                             F  135.000 DX                                                                           .000 1.919                                                                              .000                                                                               .000                                                                              R  1.50 m                                             F  194.000 DX                                                                           .000 3.445                                                                              .000                                                                               .000                                                                              R  1.50 m                                             F  28.800 DX                                                                            .000 .247                                                                               .000                                                                               .000                                                                              R  2.00 m                                             F  35.000 DX                                                                            .000 .289                                                                               .000                                                                               .000                                                                              R  2.00 m                                             F  85.000 DX                                                                            .000 .738                                                                               .000                                                                               .000                                                                              R  2.00 m                                             F  135.000 DX                                                                           .000 1.501                                                                              .000                                                                               .000                                                                              R  2.00 m                                             F  194.000 DX                                                                           .000 2.813                                                                              .000                                                                               .000                                                                              R  2.00 m                                             F  28.800 DX                                                                            .000 .163                                                                               .000                                                                               .000                                                                              R  3.00 m                                             F  35.000 DX                                                                            .000 .191                                                                               .000                                                                               .000                                                                              R  3.00 m                                             F  50.000 DX                                                                            .000 .269                                                                               .000                                                                               .000                                                                              R  3.00 m                                             F  85.000 DX                                                                            .000 .499                                                                               .000                                                                               .000                                                                              R  3.00 m                                             F  135.000 DX                                                                           .000 1.050                                                                              .000                                                                               .000                                                                              R  3.00 m                                             F  194.000 DX                                                                           .000 2.082                                                                              .000                                                                               .000                                                                              R  3.00 m                                             F  28.800 DX                                                                            .000 .097                                                                               .000                                                                               .000                                                                              R  5.00 m                                             F  35.000 DX                                                                            .000 .114                                                                               .000                                                                               .000                                                                              R  5.00 m                                             F  50.000 DX                                                                            .000 .162                                                                               .000                                                                               .000                                                                              R  5.00 m                                             F  85.000 DX                                                                            .000 .310                                                                               .000                                                                               .000                                                                              R  5.00 m                                             F  135.000 DX                                                                           .000 .659                                                                               .000                                                                               .000                                                                              R  5.00 m                                             F  194.000 DX                                                                           .000 1.387                                                                              .000                                                                               .000                                                                              R  5.00 m                                             __________________________________________________________________________

The rate of change of the conversion coefficient γ_(x) with respect to the amount x of movement in the direction of the optical axis and the rate of change of the conversion coefficient γ_(a) with respect to the angle a of rotation of the rotatable lens barrel will be examined below in association with a case in which the amount of rotation corresponding to the zooming from the wide-angle end to the telephoto end and the ratio of amounts of rotation (a_(F) /a_(Z)) with respect to the focusing from the infinity in-focus state to the closest in-focus state are set to be 1.0 in the fifth embodiment of the present invention, like in an embodiment of Japanese Patent Application Laid-open No. 5-142475 mentioned above. Note that the amount of rotation for zooming from the wide-angle end to the telephoto end and the amount of rotation for focusing are respectively re-set to be 10.0 for the purpose of a comparison with an embodiment of the present invention.

Table 10 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam in a case in which the ratio of the amounts of rotation (a_(F) /a_(Z)) is set to be 1.0 in the fifth embodiment of the present invention, like in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 (said case will be hereinafter called the comparative example II).

The upper table in Table 10 summarizes the focal length data and principal point interval data of the respective lens units of the optical system corresponding to the comparative example II. In this table, F1, F2, F3, F4 and F5 are respectively the focal lengths of first, second, third and fourth lens units, and D1, D2, D3, and D4 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, the principal point interval between the fourth and fifth lens units, and the principal point interval between the fourth lens unit and a predetermined imaging plane in six zooming states (focal lengths F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 70.0 (4-POS), 95.0 (5-POS), and 126.0 mm (6-POS)).

The middle table in Table 10 summarizes spline sample point data when the shape of the focus cam in the fourth lens unit which is used for focusing is expressed by a spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4) and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 10 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=28.8, 35.0, 50.0, 70.0, 95.0, and 126.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) using the focus cam. Since both the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=126.0) and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.80 m) are 10.0, the rotation amount ratio (a_(F) /a_(z)) of the amount of rotation for focusing to the amount of rotation for zooming is 1.0.

                                      TABLE 10                                     __________________________________________________________________________     F = 28.8-126.0 Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.00)                 __________________________________________________________________________     Focal Lengths and Principal Point Intervals of Lens Units of Comparative       Example II                                                                              1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                              6-POS                                           __________________________________________________________________________            F 28.8000                                                                            35.0000                                                                             50.0000                                                                            70.0000                                                                             95.0000                                                                            126.0000                                        F1                                                                               98.0000                                                                             D1                                                                               9.3696                                                                             15.5678                                                                             26.0774                                                                            35.1343                                                                             42.9607                                                                            49.3378                                         F2                                                                               -20.2000                                                                            D2                                                                               34.5121                                                                            30.5093                                                                             24.1872                                                                            19.0594                                                                             14.7856                                                                            10.6994                                         F3                                                                               21.3000                                                                             D3                                                                               8.9319                                                                             9.5307                                                                              10.6727                                                                            11.7442                                                                             12.4611                                                                            13.1911                                         F4                                                                               -19.6000                                                                            D4                                                                               14.4820                                                                            13.8832                                                                             12.7412                                                                            11.6697                                                                             10.9528                                                                            10.2228                                         F5                                                                               35.5000                                                                             D5                                                                               49.8013                                                                            51.5975                                                                             55.0237                                                                            58.2383                                                                             61.1451                                                                            63.0195                                         __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) of Comparative             Example                                                                        II                                                                                 ANGLE                                                                              (1)    (2)                                                                               (3)    (4)  (5)                                              __________________________________________________________________________     1   .0000                                                                              .0000  .0000                                                                             .0000  .0000                                                                               .0000                                            2   4.2963                                                                             .0000  .0000                                                                             .0000  -.0524                                                                              .0000                                            3   5.6678                                                                             .0000  .0000                                                                             .0000  -.0886                                                                              .0000                                            4   6.8749                                                                             .0000  .0000                                                                             .0000  -.1351                                                                              .0000                                            5   7.8043                                                                             .0000  .0000                                                                             .0000  -.1832                                                                              .0000                                            6   9.1848                                                                             .0000  .0000                                                                             .0000  -.2845                                                                              .0000                                            7   10.0000                                                                            .0000  .0000                                                                             .0000  -.3653                                                                              .0000                                            8   14.2963                                                                            .0000  .0000                                                                             .0000  -1.2787                                                                             .0000                                            9   15.6678                                                                            .0000  .0000                                                                             .0000  -1.9076                                                                             .0000                                            10  16.8749                                                                            .0000  .0000                                                                             .0000  -2.7174                                                                             .0000                                            11  17.8043                                                                            .0000  .0000                                                                             .0000  -3.5551                                                                             .0000                                            12  19.1848                                                                            .0000  .0000                                                                             .0000  -5.3209                                                                             .0000                                            13  20.0000                                                                            .0000  .0000                                                                             .0000  -6.7318                                                                             .0000                                            __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Comparative Example II                                                         Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.00)                                __________________________________________________________________________                    Infinity        Amount of                                                      Correspond-                                                                          Photograph-                                                                              Rotation for                                    Focal Length   ing Position                                                                         ing Distance                                                                             Focusing                                        __________________________________________________________________________     28.8 mm        .0000  5.00 m   4.296                                           35.0 mm        1.3838                                                                                3.00 m   5.668                                           50.0 mm        3.7931                                                                                2.00 m   6.875                                           70.0 mm        6.0270                                                                                1.50 m   7.804                                           95.0 mm        8.0868                                                                                1.00 m   9.185                                           126.0 mm       10.0000                                                                               0.80 m   10.000                                          Condition Corresponding Value (1)                                                                    1.31                                                     Condition Corresponding Value (2)                                                                   17.44                                                     Condition Corresponding Value (3)                                                                    1.00                                                     Condition Corresponding Value (4)                                                                   14.24 (wide-angle end)                                                         21.70 (telephoto end)                                     Condition Corresponding Value (5)                                                                    4.76 (wide-angle end)                                                         6.58 (telephoto end)                                      Condition Corresponding Value (6)                                                                    0.34 (wide-angle end)                                                          0.28 (telephoto end)                                     __________________________________________________________________________

Table 11 below summarizes the numerical value data of the cams of the focusing lens unit in the comparative example II, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 10. In this table, (ANGLE) is the angle of rotation of the rotatable lens barrel, (4) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 11                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Units in Comparative                 Example II                                                                                      Zoom Comparative Cam                                          Focus Cam numerical Value Data                                                                  Numerical Value Data                                          ANGLE (4)       F        ANGLE   (4)   F                                       ______________________________________                                         .0000 .0000     28.8000  .0000   .0000 28.8000                                 .5000 -.0039    30.8977  .5000   .4276 30.8977                                 1.0000                                                                               -.0079    33.1447  1.0000  .8636 33.1447                                 1.5000                                                                               -.0124    35.5868  1.5000  1.3155                                                                               35.5868                                 2.0000                                                                               -.0173    38.2569  2.0000  1.7855                                                                               38.2569                                 2.5000                                                                               -.0231    41.1789  2.5000  2.2688                                                                               41.1789                                 3.0000                                                                               -.0297    44.3685  3.0000  2.7579                                                                               44.3685                                 3.5000                                                                               -.0374    47.8358  3.5000  3.2440                                                                               47.8358                                 4.0000                                                                               -.0464    51.5859  4.0000  3.7188                                                                               51.5859                                 4.5000                                                                               -.0569    55.6175  4.5000  4.1839                                                                               55.6175                                 5.0000                                                                               -.0691    59.9543  5.0000  4.6556                                                                               59.9543                                 5.5000                                                                               -.0833    64.6457  5.5000  5.1530                                                                               64.6457                                 6.0000                                                                               -.0998    69.7157  6.0000  5.6946                                                                               69.7157                                 6.5000                                                                               -.1189    75.1502  6.5000  6.2879                                                                               75.1502                                 7.0000                                                                               -.1408    80.9450  7.0000  6.8895                                                                               80.9450                                 7.5000                                                                               -.1660    87.1351  7.5000  7.4492                                                                               87.1351                                 8.0000                                                                               -.1951    93.7913  8.0000  7.9384                                                                               93.7913                                 8.5000                                                                               -.2291    101.0094 8.5000  8.3526                                                                               101.0094                                9.0000                                                                               -.2684    108.8867 9.0000  8.7143                                                                               108.8867                                9.5000                                                                               -.3139    117.4149 9.5000  9.0402                                                                               117.4149                                10.0000                                                                              -.3653    126.0000 10.0000 9.3243                                                                               126.0000                                10.5000                                                                              -.4227    .0000                                                          11.0000                                                                              -.4879    .0000                                                          11.5000                                                                              -.5633    .0000                                                          12.0000                                                                              -.6511    .0000                                                          12.5000                                                                              -.7536    .0000                                                          13.0000                                                                              -.8731    .0000                                                          13.5000                                                                              -1.0119   .0000                                                          14.0000                                                                              -1.1724   .0000                                                          14.5000                                                                              -1.3569   .0000                                                          15.0000                                                                              -1.5693   .0000                                                          15.5000                                                                              -1.8160   .0000                                                          16.0000                                                                              -2.1031   .0000                                                          16.5000                                                                              -2.4356   .0000                                                          17.0000                                                                              -2.8180   .0000                                                          17.5000                                                                              -3.2565   .0000                                                          18.0000                                                                              -3.7613   .0000                                                          18.5000                                                                              -4.3476   .0000                                                          19.0000                                                                              -5.0362   .0000                                                          19.5000                                                                              -5.8441   .0000                                                          20.0000                                                                              -6.7318   .0000                                                          ______________________________________                                    

The left table in Table 11 summarizes the numerical value data of the focus cam in the comparative example II, and the right table in Table 11 summarizes the numerical value data of the zoom compensation cam of the comparative example II. A value obtained by synthesizing the amount (4) of movement in the direction of the optical axis in the numerical value data of the focus cam and the amount (4) of movement in the direction of the optical axis in the numerical value data of the zoom compensation cam in a range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) agrees with the movement locus of the fourth lens unit calculated using the paraxial data in the upper table in Table 10.

Tables 12, 13, and 14 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(k) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=70.0), and the telephoto end (F=126.0), respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), 4), and 5) on the right side respectively represent the first, second, third, fourth, and fifth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0 and 0.8 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(k) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m).

                                      TABLE 12                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End                                                                 (28.8 mm) in Comparative Example II                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.026                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.052                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.089                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.135                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.183                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.284                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.365                                                                              5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in Comparative Example II                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.295                                                                              3)                                                                               -.541                                                                              4)                                                                               -4.568                                                                             5)                                                                               -.403                                   R 10.000                                                                             ANG                                                                               2.729                                                                              1)                                                                               -.010                                                                              2)                                                                               -.291                                                                              3)                                                                               -.542                                                                              4)                                                                               -4.570                                                                             5)                                                                               -.403                                   R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               -.020                                                                              2)                                                                               -.287                                                                              3)                                                                               -.543                                                                              4)                                                                               -4.571                                                                             5)                                                                               -.403                                   R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               -.035                                                                              2)                                                                               -.281                                                                              3)                                                                               -.545                                                                              4)                                                                               -4.573                                                                             5)                                                                               -.403                                   R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               -.055                                                                              2)                                                                               -.274                                                                              3)                                                                               -.547                                                                              4)                                                                               -4.575                                                                             5)                                                                               -.403                                   R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               -.076                                                                              2)                                                                               -.266                                                                              3)                                                                               -.549                                                                              4)                                                                               -4.578                                                                             5)                                                                               -.403                                   R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               -.125                                                                              2)                                                                               -.250                                                                              3)                                                                               -.554                                                                              4)                                                                               -4.583                                                                             5)                                                                               -.403                                   R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.168                                                                              2)                                                                               -.238                                                                              3)                                                                               -.557                                                                              4)                                                                               -4.587                                                                             5)                                                                               -.403                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle End (28.8                                                   mm) in Comparative Example II                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.225                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.227                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.229                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.231                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.235                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.239                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.246                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.252                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in Comparative            Example II                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.008                                                                              5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.013                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.021                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.032                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.045                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.059                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.089                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.109                                                                              5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End (28.8                                               mm) in Comparative Example II                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .025                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .042                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .069                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .104                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .146                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .192                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .290                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .353                                                                               5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 =               γ.sub.aR /γ.sub.a0 = 14.24                                   

                                      TABLE 13                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle Position                                                                (70.0 mm) in Comparative Example II                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.704                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.146                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.237                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.294                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.671                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.496                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.903                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.754                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.822                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.021                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.578                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.019                                                                             5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Lens Units at Middle Position       (70.0 mm) in Comparative                                                       Example II                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.473                                                                              3)                                                                               -.774                                                                              4)                                                                               -3.044                                                                             5)                                                                               -.641                                   R 10.000                                                                             ANG                                                                               2.704                                                                              1)                                                                               -.010                                                                              2)                                                                               -.463                                                                              3)                                                                               -.780                                                                              4)                                                                               -3.051                                                                             5)                                                                               -.641                                   R 5.000                                                                              ANG                                                                               4.237                                                                              1)                                                                               -.021                                                                              2)                                                                               -.452                                                                              3)                                                                               -.786                                                                              4)                                                                               -3.059                                                                             5)                                                                               -.641                                   R 3.000                                                                              ANG                                                                               5.671                                                                              1)                                                                               -.035                                                                              2)                                                                               -.438                                                                              3)                                                                               -.795                                                                              4)                                                                               -3.069                                                                             5)                                                                               -.641                                   R 2.000                                                                              ANG                                                                               6.903                                                                              1)                                                                               -.055                                                                              2)                                                                               -.420                                                                              3)                                                                               -.806                                                                              4)                                                                               -3.082                                                                             5)                                                                               -.641                                   R 1.500                                                                              ANG                                                                               7.822                                                                              1)                                                                               -.077                                                                              2)                                                                               -.402                                                                              3)                                                                               -.817                                                                              4)                                                                               -3.096                                                                             5)                                                                               -.641                                   R 1.000                                                                              ANG                                                                               9.204                                                                              1)                                                                               -.128                                                                              2)                                                                               -.366                                                                              3)                                                                               -.840                                                                              4)                                                                               -3.124                                                                             5)                                                                               -.641                                   R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.173                                                                              2)                                                                               -.339                                                                              3)                                                                               -.859                                                                              4)                                                                               -3.147                                                                             5)                                                                               -.641                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle Position                                                        (70.0 mm) in Comparative Example II                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.390                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.704                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.409                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.237                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.428                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.671                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.454                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.903                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.487                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.822                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.521                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.594                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.652                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Middle Position (70.0 mm) in Comparative           Example II                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.036                                                                              5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.704                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.078                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.237                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.115                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.671                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.173                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.903                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.252                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.822                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.330                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.490                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.623                                                                              5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position                                                    (70.0 mm) in Comparative Example II                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .122                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.704                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .267                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.237                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .394                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.671                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .596                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.903                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .879                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.822                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.162                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.761                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               2.275                                                                              5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.08,         γ.sub.aR /γ.sub.a0 = 18.73                                   

                                      TABLE 14                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End                                                                  (126.0 mm) in Comparative Example II                                           R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.777                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.452                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.913                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.542                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.352                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.190                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.956                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -6.366                                                                             5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Telephoto End (126.0       mm) in Comparative                                                             Example II                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               -.000                                                                              2)                                                                               -.710                                                                              3)                                                                               -.890                                                                              4)                                                                               -2.626                                                                             5)                                                                               -.775                                   R 10.000                                                                             ANG                                                                               2.777                                                                              1)                                                                               -.010                                                                              2)                                                                               -.686                                                                              3)                                                                               -.908                                                                              4)                                                                               -2.649                                                                             5)                                                                               -.775                                   R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               -.021                                                                              2)                                                                               -.663                                                                              3)                                                                               -.927                                                                              4)                                                                               -2.673                                                                             5)                                                                               -.775                                   R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               -.036                                                                              2)                                                                               -.632                                                                              3)                                                                               -.952                                                                              4)                                                                               -2.705                                                                             5)                                                                               -.775                                   R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               -.056                                                                              2)                                                                               -.595                                                                              3)                                                                               -.985                                                                              4)                                                                               -2.746                                                                             5)                                                                               -.775                                   R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               -.078                                                                              2)                                                                               -.559                                                                              3)                                                                               -1.019                                                                             4)                                                                               -2.789                                                                             5)                                                                               -.775                                   R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               -.130                                                                              2)                                                                               -.491                                                                              3)                                                                               -1.092                                                                             4)                                                                               -2.879                                                                             5)                                                                               -.775                                   R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               -.176                                                                              2)                                                                               -.442                                                                              3)                                                                               -1.150                                                                             4)                                                                               -2.951                                                                             5)                                                                               -.775                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto End                                                          (126.0 mm) in Comparative Example II                                           R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.543                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.777                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.617                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.692                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.795                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.931                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.073                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.380                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.632                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Telephoto End (126.0 mm) in Comparative            Example II                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.109                                                                              5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.777                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.241                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.373                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.560                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.791                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.024                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.588                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.802                                                                             5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (126.0 mm) in Comparative Example II                                           R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .090                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .385                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               2.777                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .871                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               4.296                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.378                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               5.668                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               2.124                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               6.875                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               3.107                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               7.804                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               4.172                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               9.185                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               6.955                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               10.000                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               8.348                                                                              5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.31,         γ.sub.aR /γ.sub.a0 = 21.70                                   

As can be seen from Tables 12, 13, and 14, the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope (dx/da) of the focus cam at the respective focal lengths increase as the photographing distance becomes closer to the closest distance. Especially, the slope (dx/da) of the focus cam changes largely. Therefore, as can be seen from these tables, the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of γ_(x) and (dx/da), further increases.

More specifically, in a zoom lens in which the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit in a closest in-focus state is larger than that in an infinity in-focus state, i.e., which satisfies:

    1.0<γ.sub.xR /γ.sub.xO

when the focus cam which satisfies the following inequality, i.e., the focus cam has a shape having a larger slope (dx/da) at the closest corresponding position than that at the infinity corresponding position:

    1.0<<(dx/da).sub.R /(dx/da).sub.O

the following inequality is satisfied:

    1.0<γ.sub.xR /γ.sub.xO <<γ.sub.aR /γ.sub.aO

The rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel undesirably becomes larger than the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis.

From Tables 12, 13, and 14 above, the rate of change of γ_(a) is ×14.24 at the wide-angle end (F=28.8), ×18.73 at the middle position (F=70.0), and ×21.70 at the telephoto end (F=126.0).

As described above, when the conversion coefficient γ changes in correspondence with the lens arrangement (e.g., focusing), as described in Japanese Patent Application Laid-Open No. 3-228006, a plurality of pairs of data of the conversion coefficient γ and the correction coefficient ε must be stored in the storage means in units of a plurality of divided focus ranges. Therefore, when the rate of change of γ_(a) is large (γ_(aR) /γ_(aO) >>1.0), the number of divisions increases, and the storage capacity inevitably becomes large, resulting in an increase in cost. For example, when a change in γ_(a) in a single focus range is divided under the condition defined by the following inequality:

    γ.sub.max /γ.sub.min <1.2

the number N of divisions is expressed by inequality (a) below:

    N>log (γ.sub.MAX /γ.sub.MIN) /log (1.2)

Therefore, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end have large values as follows:

    N.sub.W >14.6 N.sub.M >16.1 N.sub.T >16.9

The formula K=γ(1+ε·ΔBf) presented by Japanese Patent Application Laid-Open No. 62-170924 is rewritten to the conversion coefficient K_(a) associated with the angle a of rotation of the rotatable lens barrel:

    K.sub.a =γ.sub.a (1+ε·ΔBf)

Then, the following formula is defined by using a correction coefficient μ (ε=-1/μ):

    K.sub.a =γ.sub.a (1-ΔBf/μ)

Tables 15, 16, and 17 below summarize the calculation results of the values of the conversion coefficient K_(a) and the correction coefficient μ according to the comparative example II at the wide-angle end (F=28.8), middle position (F=70.0), and telephoto end (F=126.0) using the above formula.

In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 mm), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 15, 16, and 17, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and an object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 15, 16, and 17, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.80, 10.0), and it indicates that this position corresponds to the closest in-focus (R=0.80 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=0.80 m) object, and the tenth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.80 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the tenth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.80 m) object to an in-focus state at the object distance in the second column.

From the above formulas, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μ is calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eighth row, fourth column in first table: 0.118) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=0.80 m) in Table 15 is calculated by K_(a) =1.18/10.0=0.118 using ΔBf=1.18 and Δa=10.0. On the other hand, the value of the correction coefficient μ (eighth row, fourth column in second table: -0.31) is calculated as μ=-0.31 using ΔBf=1.18, K_(a) =0.118, and γ_(a) =0.025.

                                      TABLE 15                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and                                                 Correction Coefficient μ; (l) at Wide-angle End (28.8 mm) in                Comparative Example II                                                         F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             2.729                                                                              5.000                                                                              4.296                                                                              3.000                                                                              5.668                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .025                                                                               .000    .031    .039    .050                                        2  10.000  .031                                                                               .042                                                                               .000    .055    .069                                        3  5.000   .039    .055                                                                               .069                                                                               .000    .085                                        4  3.000   .050    .069    .085                                                                               .104                                                                               .000                                        5  2.000   .063    .085    .104    .125                                        6  1.500   .076    .100    .120    .143                                        7  1.000   .100    .129    .153    .180                                        8  .800    .118    .151    .177    .207                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               -.30                                                                               -.17                                                                               -.40                                                                               -.29                                                                               -.56                                        2  10.000                                                                             .08 -.35                                                                               .00 .00 -.09                                                                               -.42                                                                               -.20                                                                               -.60                                        3  5.000                                                                              .17 -.29                                                                               .09 -.30                                                                               .00 .00 -.12                                                                               -.64                                        4  3.000                                                                              .29 -.28                                                                               .20 -.33                                                                               .12 -.48                                                                               .00 .00                                         5  2.000                                                                              .44 -.28                                                                               .35 -.35                                                                               .27 -.52                                                                               .15 -.77                                        6  1.500                                                                              .59 -.29                                                                               .51 -.37                                                                               .42 -.56                                                                               .31 -.82                                        7  1.000                                                                              .92 -.30                                                                               .84 -.41                                                                               .75 -.61                                                                               .63 -.87                                        8  .800                                                                               1.18                                                                               31  1.10                                                                               -.43                                                                               1.01                                                                               -.64                                                                               .90 -.91                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              6.875                                                                              1.500                                                                              7.804                                                                              1.000                                                                              9.185                                                                              .800                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .064    .076    .100    .119                                        2  10.000  .085    .100    .130    .152                                        3  5.000   .104    .121    .154    .178                                        4  3.000   .125    .143    .181    .207                                        5  2.000                                                                              .146                                                                               .000    .168    .210    .239                                        6  1.500   .167                                                                               .192                                                                               .000    .238    .269                                        7  1.000   .209    .238                                                                               .290                                                                               .000    .322                                        8  .800    .239    .269    .322                                                                               .353                                                                               .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.44                                                                               -.77                                                                               -.59                                                                               -.98                                                                               -.92                                                                               -1.41                                                                              -1.19                                                                              -1.79                                       2  10.000                                                                             -.35                                                                               -.84                                                                               -.51                                                                               -1.07                                                                              -.84                                                                               -1.52                                                                              -1.10                                                                              -1.93                                       3  5.000                                                                              -.27                                                                               -.91                                                                               -.42                                                                               -1.14                                                                              -.75                                                                               -1.61                                                                              -1.02                                                                              -2.05                                       4  3.000                                                                              -.15                                                                               -1.01                                                                              -.31                                                                               -1.21                                                                              -.64                                                                               -1.69                                                                              -.90                                                                               -2.18                                       5  2.000                                                                              .00 .00 -.16                                                                               -1.24                                                                              -.48                                                                               -1.76                                                                              -.75                                                                               -2.32                                       6  1.500                                                                              .16 -1.08                                                                              .00 .00 -.33                                                                               -1.85                                                                              -.59                                                                               -2.50                                       7  1.000                                                                              .48 -1.13                                                                              .33 -1.37                                                                              .00 .00 -.26                                                                               -3.02                                       8  .800                                                                               .75 -1.19                                                                              .59 -1.47                                                                              .26 -2.35                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 4.76, K.sub.aR      /γ.sub.aR = 0.34                                                   

                                      TABLE 16                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and                                                 Correction Coefficient μ; (l) at Wide-angle End (70.0 mm) in                Comparative Example II                                                         F = 70.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             2.704                                                                              5.000                                                                              4.237                                                                              3.000                                                                              5.671                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .122                                                                               .000    .183    .237    .300                                        2  10.000  .183                                                                               .267                                                                               .000    .331    .405                                        3  5.000   .236    .330                                                                               .394                                                                               .000    .484                                        4  3.000   .298    .404    .483                                                                               .596                                                                               .000                                        5  2.000   .374    .498    .596    .728                                        6  1.500   .448    .589    .702    .849                                        7  1.000   .593    .765    .902    1.074                                       8  .800    .702    .897    1.050   1.242                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.50                                                                               -1.58                                                                              -1.00                                                                              -2.52                                                                              -1.70                                                                              -3.42                                       2  10.000                                                                             .50 -.98                                                                               .00 .00 -.51                                                                               -3.16                                                                              -1.20                                                                              -3.76                                       3  5.000                                                                              1.00                                                                               -1.06                                                                              .51 -2.13                                                                              .00 .00 -.69                                                                               -3.70                                       4  3.000                                                                              1.69                                                                               -1.16                                                                              1.20                                                                               -2.34                                                                              .69 -3.06                                                                              .00 .00                                         5  2.000                                                                              2.58                                                                               -1.24                                                                              2.09                                                                               -2.41                                                                              1.59                                                                               -3.10                                                                              .90 -4.05                                       6  1.500                                                                              3.51                                                                               -1.30                                                                              3.02                                                                               -2.50                                                                              2.52                                                                               -3.22                                                                              1.83                                                                               -4.30                                       7  1.000                                                                              5.46                                                                               -1.41                                                                              4.97                                                                               -2.66                                                                              4.48                                                                               -3.48                                                                              3.80                                                                               -4.73                                       8  .800                                                                               7.02                                                                               -1.47                                                                              6.54                                                                               -2.77                                                                              6.05                                                                               -3.64                                                                              5.37                                                                               -4.96                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              6.875                                                                              1.500                                                                              7.804                                                                              1.000                                                                              9.185                                                                              .800                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .377    .452    .600    .711                                        2  10.000  .501    .594    .773    .907                                        3  5.000   .598    .706    .909    1.060                                       4  3.000   .730    .853    1.081.  1.251                                       5  2.000                                                                              .879                                                                               .000    1.016   1.269   1.458                                       6  1.500   1.014                                                                              1.162                                                                              .000    1.435   1.644                                       7  1.000   1.263   1.432                                                                              1.762                                                                              .000    2.008                                       8  .800    1.450   1.639   2.007                                                                              2.275                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -2.60                                                                              -4.55                                                                              -3.54                                                                              -5.79                                                                              -5.52                                                                              -8.38                                                                              -7.11                                                                              -10.35                                      2  10.00.0                                                                            -2.10                                                                              -4.89                                                                              -3.04                                                                              -6.22                                                                              -5.03                                                                              -8.96                                                                              -6.62                                                                              -11.00                                      3  5.000                                                                              -1.59                                                                              -4.99                                                                              -2.53                                                                              -6.45                                                                              -4.52                                                                              -9.33                                                                              -6.11                                                                              -11.44                                      4  3.000                                                                              -.90                                                                               -5.29                                                                              -1.83                                                                              -6.89                                                                              -3.82                                                                              -9.89                                                                              -5.41                                                                              -12.02                                      5  2.000                                                                              .00 .00 -.93                                                                               -7.43                                                                              -2.92                                                                              -10.42                                                                             +4.51                                                                              -12.57                                      6  1.500                                                                              .93 -6.07                                                                              .00 .00 -1.98                                                                              -10.70                                                                             -3.58                                                                              -12.91                                      7  1.000                                                                              2.91                                                                               -6.66                                                                              1.98                                                                               -8.54                                                                              .00 .00 -1.60                                                                              -13.61                                      8  .800                                                                               4.49                                                                               -6.91                                                                              3.57                                                                               -8.70                                                                              1.60                                                                               -11.50                                                                             .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 5.78, K.sub.aR      /γ.sub.aR = 0.31                                                   

                                      TABLE 17                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and                                                 Correction Coefficient μ; (l) at Wide-angle End (126.0 mm) in               Comparative Example II                                                         F = 126.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             2.704                                                                              5.000                                                                              4.237                                                                              3.000                                                                              5.671                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .385                                                                               .000    .584    .771    .999                                        2  10.000  .582                                                                               .871                                                                               .000    1.110   1.398                                       3  5.000   .765    1.107                                                                              1.379                                                                              .000    1.717                                       4  3.000   .991    1.392   1.714                                                                              2.125                                                                              .000                                        5  2.000   1.264   1.738   2.121   2.592                                       6  1.500   1.533   2.075   2.509   3.035                                       7  1.000   2.090   2.772   3.317   3.976                                       8  .800    2.531   3.322   3.953   4.715                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -1.62                                                                              -4.93                                                                              -3.31                                                                              -7.51                                                                              -5.66                                                                              -10.69                                      2  10.000                                                                             1.62                                                                               -3.16                                                                              .00 .00 -1.69                                                                              -8.66                                                                              -4.04                                                                              -11.81                                      3  5.000                                                                              3.29                                                                               -3.33                                                                              1.68                                                                               -6.19                                                                              .00 .00 -2.35                                                                              -12.25                                      4  3.000                                                                              5.62                                                                               -3.57                                                                              4.02                                                                               -6.72                                                                              2.35                                                                               -9.66                                                                              .00 .00                                         5  2.000                                                                              8.69                                                                               -3.81                                                                              7.12                                                                               -7.15                                                                              5.47                                                                               -10.16                                                                             3.13                                                                               -14.24                                      6  1.500                                                                              11.96                                                                              -4.01                                                                              10.43                                                                              -7.54                                                                              8.80                                                                               -10.74                                                                             6.48                                                                               -15.15                                      7  1.000                                                                              19.19                                                                              -4.33                                                                              17.76                                                                              -8.13                                                                              16.22                                                                              -11.53                                                                             13.98                                                                              -16.06                                      8  .800                                                                               25.31                                                                              -4.54                                                                              23.99                                                                              -8.52                                                                              22.55                                                                              -12.08                                                                             20.43                                                                              -16.76                                      __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              6.875                                                                              1.500                                                                              7.804                                                                              1.000                                                                              9.185                                                                              .800                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    1.272   1.533   2.034   2.379                                       2  10.000  1.742   2.066   2.683   3.103                                       3  5.000   2.119   2.491   3.200   3.676                                       4  3.000   2.587   3.008   3.825   4.367                                       5  2.000                                                                              3.107                                                                              .000    3.590   4.551   5.172                                       6  1.500   3.616                                                                              4.178                                                                              .000    5.298   5.989                                       7  1.000   4.726   5.467                                                                              6.953                                                                              .000    7.616                                       8  .800    5.586   6.435   7.943                                                                              8.360                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -8.75                                                                              -14.81                                                                             -11.97                                                                             -18.90                                                                             -18.68                                                                             -26.40                                                                             -23.79                                                                             -33.26                                      2  10.000                                                                             -7.14                                                                              -16.25                                                                             -10.39                                                                             -20.55                                                                             -17.19                                                                             -28.00                                                                             -22.41                                                                             -35.64                                      3  5.000                                                                              -5.46                                                                              -17.19                                                                             -8.74                                                                              -21.64                                                                             -15.64                                                                             -28.97                                                                             -20.96                                                                             -37.42                                      4  3.000                                                                              -3.12                                                                              -18.64                                                                             -6.43                                                                              -22.95                                                                             -13.45                                                                             -29.91                                                                             -18.92                                                                             -39.62                                      5  2.000                                                                              .00 .00 -3.34                                                                              -23.74                                                                             -10.51                                                                             -30.43                                                                             -16.16                                                                             -42.38                                      6  1.500                                                                              3.36                                                                               -20.51                                                                             .00 .00 -7.31                                                                              -30.73                                                                             -13.15                                                                             -46.37                                      7  1.000                                                                              10.92                                                                              -20.95                                                                             7.55                                                                               -24.46                                                                             .00 .00 -6.21                                                                              -69.71                                      8  .800                                                                               17.46                                                                              -21.88                                                                             14.13                                                                              -26.15                                                                             6.48                                                                               -45.45                                                                             .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 6.58, K.sub.aR      /γ.sub.aR = 0.28                                                   

As can be seen from Tables 15, 16, and 17 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) and a change in correction coefficient μ: (l) (e.g., the fourth column in the second table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) are considered, the conversion coefficient K_(a) and the correction coefficient μ considerably change depending on the object positions. In particular, the conversion coefficient K_(a) has a larger value at the closest object side than that at the infinity object side. Since the conversion coefficient K_(a) in the direction of rotation is defined by K_(a) =ΔBf/Δa, the amount Δa of rotation for focusing at the infinity object side becomes larger than that at the closest object side relative to the defocus amount ΔBf.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end (F=28.8), middle position (F=70.0), and telephoto end (F=126.0) in the comparative example II are as follows.

    ______________________________________                                         Comparative Example II                                                                  Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            4.76           0.34                                                 (F = 28.8)                                                                     Middle Position                                                                           5.78           0.31                                                 (F = 70.0)                                                                     Telephoto End                                                                             6.58           0.28                                                 (F = 126.0)                                                                    ______________________________________                                    

As described above, in the comparative example II, since the change in conversion coefficient K_(a) is large, the contribution of the correction term (Δf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) becomes larger, and the value of the correction coefficient μ becomes close to that of the defocus amount ΔBf. In addition, the value of the correction coefficient μ largely changes depending on the object positions.

Therefore, as described in Japanese Patent Application Laid-Open No. 3-228006, under the condition that only a pair of a conversion coefficient γ_(a) value and a correction coefficient γ value are set for a given lens arrangement range (e.g., an infinity in-focus arrangement range), if the correction coefficient γ which changes largely is represented by only one value, a large error is included in the value of the conversion coefficient K_(a) which is calculated from the conversion coefficient γ_(a) and the correction coefficient γ. Therefore, when the lens driving amount γa for focusing is finally calculated from the defocus amount ΔBf using the conversion coefficient K_(a), the lens driving amount includes an error, and an auto-focus operation cannot be accurately performed.

For example, upon calculation of the lens driving amount Δa for focusing with respect to a closest distance (R=0.80 m) object when the correction coefficient μ (which changes from -3.16 to -4.54 depending on the object distances) at the infinity in-focus arrangement at the telephoto end (F=126.0) is represented by the value (μ=-3.81) at the middle object distance (R=2.0 m), the lens driving amount Δa for focusing is calculated as Δa=8.59 by substituting ΔBf=25.31, γ_(a) =0.385, and μ=-3.81. The actual lens driving amount for focusing from the state of the infinity in-focus arrangement at the telephoto end (F=126.0) to the closest distance (R=0.80 m) object is Δa=10.0 from (R, ANGLE)=(0.80, 10.0) in the upper right portion of the third table in Table 17. Therefore, an error as large as -14.1% is produced between the actual value and the calculated value Δa=8.59 of the lens driving amount for focusing.

Similarly, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following large values are obtained.

    ______________________________________                                         Comparative Example II                                                                  Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -8.7%         -26.3%                                               (F = 28.8)                                                                     Middle Position                                                                           -13.2%         -23.4%                                               (F = 70.0)                                                                     Telephoto End                                                                             -14.1%         -28.7%                                               (F = 126.0)                                                                    ______________________________________                                    

Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (R=2.0 m), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (R=3.0 m).

Finally Table 18 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 10) of the comparative example II, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 18 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 70.0, 95.0, and 126.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and the photographing distances. In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, fourth, and fifth lens units in turn from the right side (movement toward the object side is represented by a positive value).

                                      TABLE 18                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Comparative Example II                        __________________________________________________________________________             0.80 m                                                                              1.00 m                                                                             1.50 m                                                                              2.00 m                                                                             3.00 m                                                                               5.00 m                                         __________________________________________________________________________     F 28.800 Bf                                                                            .000 .000                                                                               .000 .000                                                                               .000  .000                                           F 35.000 Bf                                                                            .000 -.013                                                                              -.017                                                                               -.009                                                                              -.007 -.003                                          F 50.000 Bf                                                                            .000 .012                                                                               -.006                                                                               -.020                                                                              -.027 -.015                                          F 70.000 Bf                                                                            .000 .035                                                                               .021 .024                                                                               .002  -.023                                          F 95.000 Bf                                                                            .000 .034                                                                               .041 .050                                                                               .023  .015                                           F 126.000 Bf                                                                           .000 .000                                                                               .000 .000                                                                               .000  .000                                           __________________________________________________________________________       ANGLE DA                                                                             10.000                                                                              9.185                                                                              7.804                                                                               6.875                                                                              5.668 4.296                                          __________________________________________________________________________     F 28.800 DX                                                                            .000 .000                                                                               .000 -.365                                                                              .000                                                                               R 0.80 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.533                                                                              .000                                                                               R 0.80 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -1.061                                                                             .000                                                                               R 0.80 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -2.019                                                                             .000                                                                               R 0.80 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -3.656                                                                             .000                                                                               R 0.80 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -6.366                                                                             .000                                                                               R 0.80 m                                         F 28.000 DX                                                                            .000 .000                                                                               .000 -.284                                                                              .000                                                                               R 1.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.420                                                                              .000                                                                               R 1.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.825                                                                              .000                                                                               R 1.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -1.568                                                                             .000                                                                               R 1.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -2.848                                                                             .000                                                                               R 1.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -4.956                                                                             .000                                                                               R 1.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.183                                                                              .000                                                                               R 1.50 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.273                                                                              .000                                                                               R 1.50 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.537                                                                              .000                                                                               R 1.50 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -1.015                                                                             .000                                                                               R 1.50 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -1.836                                                                             .000                                                                               R 1.50 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -3.190                                                                             .000                                                                               R 1.50 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.135                                                                              .000                                                                               R 2.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.201                                                                              .000                                                                               R 2.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.401                                                                              .000                                                                               R 2.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.747                                                                              .000                                                                               R 2.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -1.351                                                                             .000                                                                               R 2.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -2.352                                                                             .000                                                                               R 2.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.089                                                                              .000                                                                               R 3.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.132                                                                              .000                                                                               R 3.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.268                                                                              .000                                                                               R 3.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.495                                                                              .000                                                                               R 3.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -.890                                                                              .000                                                                               R 3.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -1.542                                                                             .000                                                                               R 3.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.052                                                                              .000                                                                               R 5.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.078                                                                              .000                                                                               R 5.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.158                                                                              .000                                                                               R 5.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.301                                                                              .000                                                                               R 5.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -.528                                                                              .000                                                                               R 5.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -.913                                                                              .000                                                                               R 5.00 m                                         __________________________________________________________________________

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a zoom lens which can suppress changes in conversion coefficient γ_(a) and correction coefficient μ above even when the focus cam is used for achieving manual focusing, can suppress the storage capacity by reducing the number of data of the conversion coefficient γ_(a) and correction coefficient μ to be stored in the storage means, can eliminate an error upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a), and can achieve accurate auto-focusing, without increasing the size of a barrel mechanism.

According to the present invention, in a zoom lens system in which the movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by the amount of movement, in the direction of the optical axis, of lens units, and the angle of rotation of a rotatable lens barrel, when the ratios (dBf/dx) of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points are respectively represented by γ_(xO) and γ_(xR), the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end are respectively represented by Δx_(WR) and Δx_(TR), and the amount of rotation of the focusing lens unit on the focus cam corresponding to zooming from the wide-angle end to the telephoto end and the amount of rotation corresponding to focusing from the infinity in-focus state to the closest in-focus state are respectively represented by a_(Z) and a_(F), the zoom lens satisfies conditional formulas (1), (2), and (3) below at least at the telephoto end:

    1.00<γ.sub.xR /γ.sub.xO                        ( 1)

    4.50<Δx.sub.TR /Δx.sub.WR <10.00               (2)

    -1.00<a.sub.F /a.sub.z <-0.60                              (3)

On the other hand, when the ratios (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane with respect to the angle da of infinitesimal rotation of the focusing lens unit on the focus cam at the infinity and closest in-focus points are respectively represented by γ_(aO) and γ_(aR), the zoom lens satisfies the following formula at least at the wide-angle end and the telephoto end:

    0.13 <γ.sub.aR /γ.sub.aO <0.80

Furthermore, when the conversion coefficients K_(a), which are used when the focusing lens unit are located at the lens arrangements corresponding to the infinity and closest in-focus states and are expressed by K_(a) =ΔBf/Δa, are respectively represented by K_(aO) and K_(aR), the zoom lens satisfies the following formulas at least at the wide-angle end and the telephoto end:

    0.50<K.sub.aO /γ.sub.aO <1.30

    0.80<K.sub.aR /γ.sub.aR <1.80

where

ΔBf: the defocus amount between the imaging position of an object at an arbitrary position and a predetermined imaging point position

Δa: the angle of rotation of the focusing lens unit on the focus cam required for attaining an in-focus state on the object

As in the above-mentioned first aspect of the present invention, in the third aspect of the present invention, since the above-mentioned conditional formulas are satisfied, even when the focus cam is used to achieve so-called manual focusing, changes in conversion coefficient γ_(a) and correction coefficient μ required for realizing accurate auto-focusing can be reduced, without a barrel mechanism in an increased size. For this reason, the number of data of the conversion coefficient γ_(a) and correction coefficient μ to be stored in the storage means can be reduced. Furthermore, since the change in correction coefficient μ is small, an error upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a) is small, and accurate auto-focusing can be realized.

As described above, when the zoom lens system is constituted by n lens units, and its k-th lens unit is used as a focusing lens unit, the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit (the ratio dBf/dx of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement in the direction of the optical axis) is expressed using the imaging magnifications β of the respective lens units as follows:

    γ.sub.x =(1-β.sub.k.sup.2)β.sub.k+1.sup.2 β.sub.k+2.sup.2. . . β.sub.n.sup.2

Therefore, the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the direction of the optical axis can be expressed using the imaging magnifications β_(Ok) and β_(Rk) of the focusing lens unit at the infinity and closest in-focus points as follows:

    γ.sub.xR /γ.sub.xO =(1-β.sub.Rk.sup.2)/(1-β.sub.Ok.sup.2)

On the other hand, the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit (the ratio dBf/da of the amount dBf of infinitesimal movement of the imaging plane to the angle da of infinitesimal rotation) can be expressed by:

    γ.sub.a =γ.sub.x ·(dx/da)

where dx/da is the slope of the focus cam. For this reason, the rate of change, from the infinity in-focus value (y_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit can be expressed using slopes (dx/da)_(O) and (dx/da)_(R) at the infinity and closest corresponding positions on the focus cam as follows:

    γ.sub.aR /γ.sub.aO =(γ.sub.xR /γ.sub.xO)·((dx/da).sub.R /(dx/da).sub.O)

Therefore, like in the present invention, in the zoom lens system in which the value of the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit in the closest in-focus state becomes larger than that in the infinity in-focus state (1.0<γ_(xR) /γ_(xO)), the ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state and the amount a_(z) of rotation corresponding to zooming from the wide-angle end to the telephoto end is set to be negative (a_(F) /a_(Z) <0), so that the focus cam can have a shape in which the slope (dx/da) at the closest corresponding position becomes smaller than that at the infinity corresponding position (0<(dx/da)_(R) /(dx/da)_(O) <1.0), thereby reducing the change in conversion coefficient γ_(a) associated with the direction of rotation.

More specifically, since the rate of change (γ_(aR) /γ_(aO)), from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the direction of rotation is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion ratio γ_(x) associated with the direction of the optical axis and the slope ratio (dx/da)_(R) /(dx/da)_(O) of the focus cam, as described above, the final rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) associated with the direction of rotation can be compressed by adopting an arrangement in which the two changes cancel out each other.

According to the present invention, in a zoom lens in which the conversion coefficients γ_(xO), γ_(xR) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points at the telephoto end satisfies conditional formula (1):

    1.00<γ.sub.xR /γ.sub.xO                        ( 1)

and the amounts Δx_(WR) and Δx_(TR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end satisfies conditional formula (2):

    4.50<Δx.sub.TR /Δx.sub.WR <10.00               (2)

the ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end is set to satisfy conditional formula (3):

    -1.00<a.sub.F /a.sub.Z <-0.60                              (3)

Under these conditions, the final rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) associated with the direction of rotation can be set to be a small value which satisfies conditional formula (4) below:

    0.13<γ.sub.aR /γ.sub.aO <0.80                  (4)

As described above, since the change in conversion coefficient γ_(a) can be reduced as compared to that in the conventional system, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced.

For example, upon division of the focus range like in formula (a) (N>log(γ_(MAX) /γ_(MIN))/log(1.2)) above, the following relation is satisfied:

    1.2<log (γ.sub.MAX /γ.sub.MIN)/log (1.2)<11.2

and the number of divisions can be smaller than in the conventional system. Therefore, cost can be reduced in terms of the storage capacity. Furthermore, as will be described later in the following description of the embodiments, since the changes in conversion coefficient K_(a) and correction coefficient μ are smaller than those in the conventional system, an error obtained upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a) is small, and an accurate auto-focusing operation can be realized.

The conditional formulas of the present invention will be explained below.

Conditional formula (1) is associated with the focusing lens unit in the zoom lens according to the present invention. When γ_(xR) /γ_(xO) is smaller than the lower limit of conditional formula (1) (γ_(xR) /γ_(xO) <1.0), the conversion coefficient γ_(x) associated with the direction of the optical axis in the closest in-focus state becomes smaller than that in the infinity in-focus state. For this reason, when the focus cam (0<(dx/da)_(R) /(dx/da)_(O) <1.0) according to the present invention is used, the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, becomes excessively smaller than 1.0 (γ_(aR) /γ_(aO) <<1.0), and changes in γ_(a) become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since the changes in conversion coefficient K_(a) and correction coefficient μ become large, the error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

Conditional formula (2) is associated with the ratio between the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end. As will be described later in the description of the embodiments, this ratio is an amount which is associated with the ratio of the slope (dx/da)_(R) at the closest corresponding position to the slope (dx/da)_(O) at the infinity corresponding position on the focus cam. As the ratio between the two amounts of movement becomes smaller, changes in slope on the focus cam become smaller. On the contrary, as the ratio between the two amounts of movement becomes larger, changes in slope on the focus cam become larger. Therefore, when the ratio is smaller than the lower limit of conditional formula (2), changes in conversion coefficient γ_(a) associated with the direction of rotation become small. However, in the zoom lens of the present invention, which satisfies conditional formula (1), the optimal ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(z) of rotation corresponding to zooming from the wide-angle end to the telephoto end falls outside a range defined by conditional formula (3). On the other hand, when the ratio exceeds the upper limit of conditional formula (2), and if said ratio of the amount of rotation is set in the conditional formula (3), since changes in slope on the focus cam become too large as compared to those in conversion coefficient γ_(x) associated with the direction of the optical axis, changes in conversion coefficient γ_(a) associated with the direction of rotation become large, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, an accurate auto-focusing operation cannot be performed.

Conditional formula (3) defines an appropriate ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(z) of rotation corresponding to zooming from the wide-angle end to the telephoto end. When the ratio is smaller than the lower limit of conditional formula (3), the slope (dx/da) of the focus cam considerably decreases at the closest corresponding position as compared to the slope at the infinity corresponding position, and they have a ratio:

    0<(dx/da).sub.R /(dx/da).sub.O <<1.0

For this reason, the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, becomes excessively smaller than 1.0 (γ_(aR) /γ_(aO) <<1.0), and changes in γ_(a) become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since changes in μ are large, an error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

On the contrary, when the ratio exceeds the upper limit of conditional formula (3), since the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes closer to 1.0, changes in γ_(a) become small, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced. However, the slope (dx/da)_(O) of the focus cam at the infinity corresponding position at the telephoto end becomes large. Therefore, it is required to increase the diameter of a cam barrel corresponding to the focus cam in order to effect a smooth focusing operation by reducing the slope angle of the cam in the barrel mechanism. Thus, it becomes impossible to maintain the barrel to be small.

Conditional formula (4) is a condition associated with the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means, i.e., the number of divisions of the focus range. When γ_(aR) /γ_(aO) is smaller than the lower limit of conditional formula (4), the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes excessively smaller than 1.0, and changes in γ_(a) become large. As a result, since the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases, a storage means with a large storage capacity is required, resulting in an increase in cost.

On the contrary, when γ_(aR) /γ_(aO) exceeds the upper limit of conditional formula (4), since the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes closer to 1.0, changes in γ_(a) become small, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced. However, since the conversion coefficient γ_(a) must have a considerably large value, the sensitivity (dBf/da) associated with the movement in the direction of rotation becomes strict, and a change in imaging point caused by a slight error factor in the direction of rotation becomes large, thus disturbing accurate auto-focusing.

Furthermore, in order to attain accurate auto-focusing while lowering the sensitivity (dBf/da) associated with the movement in the direction of rotation, the upper and lower limits of conditional formula (4) are preferably set as follows:

    0.16<γ.sub.aR /γ.sub.aO <0.70

In order to obtain a zoom lens which can perform auto-focusing more accurately, when the conversion coefficients K_(a) (=ΔBf/Δa) used when the focusing lens unit is located at the lens arrangements corresponding to the infinity in-focus state and the closest in-focus state are respectively represented by K_(aO) and K_(aR), the zoom lens preferably satisfies conditional formulas (5) and (6) below at least at the wide-angle end and the telephoto end:

    0.50<K.sub.aO /γ.sub.aO <1.30                        (5)

    0.80<K.sub.aR /γ.sub.aR <1.80                        (6)

Conditional formula (5) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the infinity in-focus state. When the rate is smaller than the lower limit of conditional formula (5), the change in conversion coefficient K_(aO) upon a change in object position becomes too small as compared to the conversion coefficient γ_(aO) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the infinity in-focus point. Therefore, for example, when the conversion coefficient K_(aO) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value on the basis of the relationship K_(aO) =γ_(aO) (1-ΔBf/μ_(aO)), a large error is produced in the value of the conversion coefficient K_(a0) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO), thus disturbing accurate auto-focusing.

On the contrary, when the rate exceeds the upper limit of conditional formula (5), the change in conversion coefficient K_(aO) in the direction of rotation upon a change in object position becomes large as compared to the conversion coefficient γ_(aO) in the direction of rotation of the focusing lens unit at the infinity in-focus point. For this reason, when the conversion coefficient K_(aO) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO).

In order to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (5) are preferably set as follows:

    0.60<K.sub.aO /γ.sub.aO <1.15

Similarly, when the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1) upon a change in object position when the focusing lens unit corresponds to an arrangement in the infinity in-focus state, the sign of the correction coefficient μ_(aO) changes before and after (K_(aO) /γ_(aO) =1). As a result, when the conversion coefficient K_(aO) is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO). Therefore, the conversion coefficient K_(aO) does not preferably change too much after it exceeds (K_(aO) /γ_(aO) =1).

Therefore, even when the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1), the zoom lens preferably satisfies the following conditional formula:

    0.60<K.sub.aO /γ.sub.aO <1.15

Conditional formula (6) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the closest in-focus position. When the rate exceeds the upper limit of conditional formula (6), the change in conversion coefficient K_(aR) in the direction of rotation upon a change in object position becomes too large as compared to the conversion coefficient γ_(aR) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the closest in-focus point. Therefore, for example, when the conversion coefficient K_(aR) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value on the basis of the relationship K_(aR) =γ_(aR) (1-ΔBf/μ_(aR)), a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) R and the correction coefficient μ_(aR), thus disturbing accurate auto-focusing.

On the contrary, when the rate is smaller than the lower limit of conditional formula (6), the change in conversion coefficient K_(aR) in the direction of rotation upon a change in object position becomes small as compared to the conversion coefficient γ_(aR) in the direction of rotation of the focusing lens unit at the closest in-focus point. For this reason, when the conversion coefficient K_(aR) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value, a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR).

In order to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (6) are preferably set as follows:

    0.90<K.sub.aR /γ.sub.aR <1.70

Similarly, when the conversion coefficient K_(aR) changes from (K_(aR) /γ_(aR) <1) to (K_(aR) /γ_(aR) >1) upon a change in object position when the focusing lens unit corresponds to an arrangement in the closest in-focus state, the sign of the correction coefficient μ_(aR) changes before and after (K_(aR) /γ_(aR) =1). As a result, when the conversion coefficient K_(aR) is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value, a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR). Therefore, the conversion coefficient K_(aR) preferably does not change too much after it exceeds (K_(aR) /γ_(aR) =1).

Therefore, even when the conversion coefficient K_(aR) changes from (K_(aR) /γ_(aR) <1) to (K_(aR) /γ_(aR) >1), the zoom lens preferably satisfies the following conditional formula:

    0.90<K.sub.aR /γ.sub.aR <1.70

According to the present invention, in a zoom lens system in which the movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by the amount of movement, in the direction of the optical axis, of lens units, and the angle of rotation of a rotatable lens barrel, when the ratios (dBf/dx) of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points are respectively represented by γ_(xO) and γ_(xR), the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end are respectively represented by Δx_(WR) and Δx_(TR), and the amount of rotation of the focusing lens unit on the focus cam corresponding to zooming from the wide-angle end to the telephoto end and the amount of rotation corresponding to focusing from the infinity in-focus state to the closest in-focus state are respectively represented by a_(Z) and a_(F), the zoom lens satisfies conditional formulas (7), (8), and (9) below at least at the telephoto end:

    1.00<γ.sub.xR /γ.sub.xO                        ( 7)

    10.00<Δx.sub.TR /Δx.sub.WR <30.00              (8)

    -1.00<a.sub.F /a.sub.Z <-0.50                              (9)

On the other hand, when the ratios (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane with respect to the angle da of infinitesimal rotation of the focusing lens unit on the focus cam at the infinity and closest in-focus points are respectively represented by γ_(aO) and γ_(aR), the zoom lens satisfies the following formula at least at the wide-angle end and the telephoto end:

    0.08<γ.sub.aR /γ.sub.aO <0.70

Furthermore, when the conversion coefficients K_(a) which are used when the focusing lens unit are located at the lens arrangements corresponding to the infinity and closest in-focus states and are expressed by K_(a) =ΔBf/Δa, are respectively represented by K_(aO) and K_(aR), the zoom lens satisfies the following formulas at least at the wide-angle end and the telephoto end:

    0.35<K.sub.aO /γ.sub.aO <1.00

    1.00<K.sub.aR /γ.sub.aR <3.00

where

ΔBf: the defocus amount between the imaging position of an object at an arbitrary position and a predetermined imaging point position

Δa: the angle of rotation of the focusing lens unit on the focus cam required for attaining an in-focus state on the object

According to the present invention, in a zoom lens in which the conversion coefficients γ_(xO), γ_(xR) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points at the telephoto end satisfies conditional formula (7):

    1.00<γ.sub.xR /γ.sub.xO                        ( 7)

and the amounts Δx_(WR) and Δx_(TR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end satisfies conditional formula (8):

    10.00<Δx.sub.TR /Δx.sub.WR <30.00              (8)

the ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end is set to satisfy conditional formula (9):

    -1.00<a.sub.F /a.sub.Z <-0.50                              (9)

Under these conditions, the final rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) associated with the direction of rotation can be set to be a small value which satisfies conditional formula (10) below:

    0.08<γ.sub.aR /γ.sub.aO <0.70                  (10)

As described above, since the change in conversion coefficient γ_(a) can be reduced as compared to that in the conventional system, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced.

For example, upon division of the focus range like in formula (a) (N>log(γ_(MAX) /γ_(MIN))/log(1.2)) above, the following relation is satisfied:

    2.0<log (γ.sub.MAX /γ.sub.MIN)/log (1.2)<13.9

and the number of divisions can be smaller than in the conventional system. Therefore, cost can be reduced in terms of the storage capacity. Furthermore, as will be described later in the following description of the embodiments, since the changes in conversion coefficient K_(a) and correction coefficient μ are smaller than those in the conventional system, an error obtained upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a) is small, and an accurate auto-focusing operation can be realized.

The conditional formulas of the present invention will be explained below.

Conditional formula (7) is associated with the focusing lens unit in the zoom lens according to the present invention. When γ_(xR) /γ_(xO) is smaller than the lower limit of conditional formula (1) (γ_(xR) /γ_(xO) <1.0), the conversion coefficient γ_(x) associated with the direction of the optical axis in the closest in-focus state becomes smaller than that in the infinity in-focus state. For this reason, when the focus cam (0<(dx/da)_(R) /(dx/da)_(O) <1.0) according to the present invention is used, the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, becomes excessively smaller than 1.0 (γ_(aR) /γ_(aO) <<1.0), and changes in γ_(a) become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since the changes in conversion coefficient K_(a) and correction coefficient μ become large, the error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

Conditional formula (8) is associated with the ratio between the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end. As will be described later in the description of the embodiments, this ratio is an amount which is associated with the ratio of the slope (dx/da)_(R) at the closest corresponding position to the slope (dx/da)_(O) at the infinity corresponding position on the focus cam. As the ratio between the two amounts of movement becomes smaller, changes in slope on the focus cam become smaller. On the contrary, as the ratio between the two amounts of movement becomes larger, changes in slope on the focus cam become larger. Therefore, when the ratio is smaller than the lower limit of conditional formula (8), changes in conversion coefficient γ_(a) associated with the direction of rotation become small. However, in the zoom lens of the present invention, which satisfies conditional formula (7), the optimal ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end falls outside a range defined by conditional formula (9). On the other hand, when the ratio exceeds the upper limit of conditional formula (8), and if said ratio of the amount of rotation is set in the conditional formula (9), since changes in slope on the focus cam become too large as compared to those in conversion coefficient γ_(x) associated with the direction of the optical axis, changes in conversion coefficient γ_(a) associated with the direction of rotation become very large, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases largely. In addition, an accurate auto-focusing operation cannot be performed. Therefore, it is more preferable to set the upper limit of the conditional formula (9) to be 20.0.

Conditional formula (9) defines an appropriate ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end. When the ratio is smaller than the lower limit of conditional formula (9), the slope (dx/da) of the focus cam considerably decreases at the closest corresponding position as compared to the slope at the infinity corresponding position, and they have a ratio:

    0<(dx/da).sub.R /(dx/da).sub.O <<1.0

For this reason, the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, becomes excessively smaller than 1.0 (γ_(aR) /γ_(aO) <<1.0), and changes in γ_(a) become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since changes in μ are large, an error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed. Therefore, it is more preferable to set the lower limit of conditional formula (9) to -0.90.

On the contrary, when the ratio exceeds the upper limit of conditional formula (9), since the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes closer to 1.0, changes in γ_(a) become small, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced. However, the slope (dx/da)_(O) of the focus cam at the infinity corresponding position at the telephoto end becomes large. Therefore, it is required to largely increase the diameter of a cam barrel corresponding to the focus cam in order to effect a smooth focusing operation by reducing the slope angle of the cam in the barrel mechanism. Thus, it becomes impossible to maintain the barrel to be small.

Conditional formula (10) is a condition associated with the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means, i.e., the number of divisions of the focus range. When γ_(aR) /γ_(aO) is smaller than the lower limit of conditional formula (10), the rate of change (γ_(aR) R/γ_(aO)) of the conversion coefficient γ_(a) becomes excessively smaller than 1.0, and changes in γ_(a) become large. As a result, since the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases, a storage means with a very large storage capacity is required, resulting in a large increase in cost.

On the contrary, when γ_(aR) /γ_(aO) exceeds the upper limit of conditional formula (10), since the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes closer to 1.0, changes in γ_(a) become small, and the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced. However, since the conversion coefficient γ_(a) must have an extremely large value, the sensitivity (dBf/da) associated with the movement in the direction of rotation becomes very strict, and a change in imaging point caused by a slight error factor in the direction of rotation becomes large, thus disturbing accurate auto-focusing.

Furthermore, in order to attain accurate auto-focusing while lowering the sensitivity (dBf/da) associated with the movement in the direction of rotation, the upper and lower limits of conditional formula (10) are preferably set as follows:

    0.10<γ.sub.aR /γ.sub.aO <0.50

In order to obtain a zoom lens which can perform auto-focusing more accurately, when the conversion coefficients K_(a) (=ΔBf/Δa) used when the focusing lens unit is located at the lens arrangements corresponding to the infinity in-focus state and the closest in-focus state are respectively represented by K_(aO) and K_(aR), the zoom lens preferably satisfies conditional formulas (11) and (12) below at least at the wide-angle end and the telephoto end:

    0.35<K.sub.aO /γ.sub.aO <1.00                        (11)

    1.00<K.sub.aR /γ.sub.aR <3.00                        (12)

Conditional formula (11) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the infinity in-focus state. When the rate is smaller than the lower limit of conditional formula (11), the change in conversion coefficient K_(aO) upon a change in object position becomes too small as compared to the conversion coefficient y_(aO) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the infinity in-focus point. Therefore, for example, when the conversion coefficient K_(aO) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value on the basis of the relationship K_(aO) =γ_(aO) (1-ΔBf/μ_(aO)), a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO), thus disturbing accurate auto-focusing. Therefore, it is more preferable to set the lower limit of conditional formula (11) to be 0.45.

On the contrary, when the rate exceeds the upper limit of conditional formula (11), the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1) upon a change in object position and, the sign of the correction coefficient μ_(aO) changes before and after (K_(aO) /γ_(aO) =1). As a result, when the conversion coefficient K_(aO) is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO).

Conditional formula (12) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the closest in-focus position. When the rate exceeds the upper limit of conditional formula (12), the change in conversion coefficient K_(aR) in the direction of rotation upon a change in object position becomes too large as compared to the conversion coefficient γ_(aR) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the closest in-focus point. Therefore, for example, when the conversion coefficient K_(aR) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value on the basis of the relationship K_(aR) =γ_(aR) (1-ΔBf/μ_(aR)), a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR), thus disturbing accurate auto-focusing. Therefore, it is further preferable to set the upper limit of conditional formula (12) to be 2.50.

On the contrary, when the rate is smaller than the lower limit of conditional formula (12), the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1) upon a change in object position, and the sign of the correction coefficient μ_(aR) changes before and after (K_(aO) /γ_(aO) =1). As a result, when the conversion coefficient K_(aO) is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the movement loci for zooming of a zoom lens, the shapes of a focus cam and a zoom compensation cam of a second lens unit in the zoom lens according to the first embodiment of the present invention;

FIG. 2 is a view for explaining the shape of the focus cam in the zoom lens according to the first embodiment of the present invention.

FIG. 3 is a view showing the movement loci for zooming of a zoom lens, the shapes of a focus cam and a zoom compensation cam of a second lens unit in the zoom lens according to the fifth embodiment of the present invention; and

FIG. 4 is a view for explaining the shape of the focus cam in the zoom lens according to the fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail hereinafter with reference to its embodiments.

First Embodiment!

A zoom lens of the first embodiment is a zoom lens which has a four-unit arrangement, i.e., positive, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.95 m) to the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=194.0) is set to be -0.65.

Table 19 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the first embodiment.

The upper table in Table 19 summarizes the focal length data, and the principal point interval data of the respective lens units of the optical system corresponding to the first embodiment.

In this table, F1, F2, F3 and F4 are respectively the focal lengths of first, second, third and fourth lens units, and D1, D2, D3, and D4 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, and the principal point interval between the fourth lens unit and a predetermined imaging plane in six zooming states (F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 85.0 (4-POS), 135.0 (5-POS), and 194.0 mm (6-POS)).

The middle table in Table 19 summarizes spline sample data when the shape (a curve g_(2F) in FIG. 1B) of the focus cam in the second lens unit of the first embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 19 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=28.8, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) using the focus cam of the first embodiment. In the lower table in Table 19, since the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=194.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.95 m) is set to be -6.5, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the first embodiment is -0.65.

                                      TABLE 19                                     __________________________________________________________________________     First Embodiment F = 28.8-194.0 (Rotation Amount Ratio:                        a.sub.F /a.sub.Z = -0.65)                                                      __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of First             Embodiment                                                                              1-POS                                                                              2-POS                                                                              3-POS                                                                              4-POS                                                                               5-POS                                                                               6-POS                                           __________________________________________________________________________            F 28.8000                                                                            35.0000                                                                            50.0000                                                                            85.0000                                                                             135.0000                                                                            194.0000                                        F1                                                                               85.0000                                                                             D1                                                                               11.5063                                                                            15.6399                                                                            23.6055                                                                            35.1974                                                                             44.4737                                                                             50.4202                                         F2                                                                               -14.7000                                                                            D2                                                                               25.8069                                                                            23.2088                                                                            19.3898                                                                            14.8844                                                                             11.1724                                                                             7.8560                                          F3                                                                               43.5000                                                                             D3                                                                               8.0000                                                                             7.3138                                                                             5.7748                                                                             3.8464                                                                              2.8540                                                                              2.0039                                          F4                                                                               61.0000                                                                             D4                                                                               59.7035                                                                            64.5166                                                                            73.5311                                                                            86.9840                                                                             97.2356                                                                             104.6041                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding              to First Embodiment                                                               ANGLE     (1)                                                                               (2)      (3)                                                                               (4)                                                __________________________________________________________________________     1  -10.0000  .0000                                                                             .6790    .0000                                                                             .0000                                              2  -6.5000   .0000                                                                             .5362    .0000                                                                             .0000                                              3  -4.4106   .0000                                                                             .4194    .0000                                                                             .0000                                              4  -3.2026   .0000                                                                             .3325    .0000                                                                             .0000                                              5  -2.2078   .0000                                                                             .2472    .0000                                                                             .0000                                              6  -1.3640   .0000                                                                             .1633    .0000                                                                             .0000                                              7  -.7750    .0000                                                                             .0973    .0000                                                                             .0000                                              8  .0000     .0000                                                                             .0000    .0000                                                                             .0000                                              9  3.5000    .0000                                                                             -.6351   .0000                                                                             .0000                                              10 5.5894    .0000                                                                             -1.3003  .0000                                                                             .0000                                              11 6.7974    .0000                                                                             -1.8632  .0000                                                                             .0000                                              12 7.7922    .0000                                                                             -2.4953  .0000                                                                             .0000                                              13 8.6360    .0000                                                                             -3.2268  .0000                                                                             .0000                                              14 9.2250    .0000                                                                             -3.9212  .0000                                                                             .0000                                              15 10.0000   .0000                                                                             -5.3084  .0000                                                                             .0000                                              16 10.5000   .0000                                                                             -6.7600  .0000                                                                             .0000                                              __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          First Embodiment                                                               Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.65)                               __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal Length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     28.8 mm        .0000  5.00 m    -.775                                          35.0 mm        .9456  3.00 m    -1.364                                         50.0 mm        2.8915                                                                                2.00 m    -2.208                                         85.0 mm        5.9442                                                                                1.50 m    -3.203                                         135.0 mm       8.5249                                                                                1.20 m    -4.411                                         194.0 mm       10.0000                                                                               0.95 m    -6.500                                         Condition Corresponding Value (1)                                                                    1.81                                                     Condition Corresponding Value (2)                                                                    8.72                                                     Condition Corresponding Value (3)                                                                   -0.65                                                     Condition Corresponding Value (4)                                                                    0.37 (wide-angle end)                                                          0.18 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.65 (wide-angle end)                                                          0.91 (telephoto end)                                     Condition Corresponding Value (6)                                                                    1.65 (wide-angle end)                                                          1.48 (telepboto end)                                     __________________________________________________________________________

Table 20 below summarizes the numerical value data of the cams of the focusing lens unit in the first embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 19. In this table, (ANGLE) is the angle of rotation of the rotatable lens barrel, (2) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 20                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in First                        Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)       F        ANGLE  (2)   F                                       ______________________________________                                         -6.5000                                                                               .5362     .0000                                                         -6.0000                                                                               .5114     .0000                                                         -5.5000                                                                               .4848     .0000                                                         -5.0000                                                                               .4561     .0000                                                         -4.5000                                                                               .4252     .0000                                                         -4.0000                                                                               .3917     .0000                                                         -3.5000                                                                               .3555     .0000                                                         -3.0000                                                                               .3162     .0000                                                         -2.5000                                                                               .2736     .0000                                                         -2.0000                                                                               .2276     .0000                                                         -1.5000                                                                               .1777     .0000                                                         -1.0000                                                                               .1234     .0000                                                         -.5000 .0641     .0000                                                         .0000  .0000     28.8000  .0000  .0000 28.8000                                 .5000  -.0685    32.0242  .5000  .8742 32.0242                                 1.0000 -.1423    35.3710  1.0000 1.7614                                                                               35.3710                                 1.5000 -.2226    38.8814  1.5000 2.7015                                                                               38.8814                                 2.0000 -.3108    42.6132  2.0000 3.7069                                                                               42.6132                                 2.5000 -.4081    46.6255  2.5000 4.7830                                                                               46.6255                                 3.0000 -.5158    50.9755  3.0000 5.9325                                                                               50.9755                                 3.5000 -.6351    55.7062  3.5000 7.1512                                                                               55.7062                                 4.0000 -.7675    60.8343  4.0000 8.4253                                                                               60.8343                                 4.5000 -.9151    66.3964  4.5000 9.7444                                                                               66.3964                                 5.0000 -1.0802   72.4133  5.0000 11.0933                                                                              72.4133                                 5.5000 -1.2650   78.8805  5.5000 12.4518                                                                              78.8805                                 6.0000 -1.4722   85.7983  6.0000 13.8029                                                                              85.7983                                 6.5000 -1.7073   93.3264  6.5000 15.1571                                                                              93.3264                                 7.0000 -1.9772   101.7016 7.0000 16.5280                                                                              101.7016                                7.5000 -2.2895   111.1184 7.5000 17.9167                                                                              111.1184                                8.0000 -2.6536   121.7895 8.0000 19.3243                                                                              121.7895                                8.5000 -3.0906   134.3107 8.5000 20.7909                                                                              134.3107                                9.0000 -3.6350   149.5900 9.0000 22.3728                                                                              149.5900                                9.5000 -4.3168   168.0630 9.5000 24.0881                                                                              168.0630                                10.0000                                                                               -5.3084   194.0000 10.0000                                                                               26.2620                                                                              194.0000                                ______________________________________                                    

The left table in Table 20 summarizes the numerical value data of the focus cam of the first embodiment, and the right table in Table 20 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE =10.0) coincides with the movement locus (a curve g₂ in FIG. 1) of the second lens unit calculated using the paraxial data in the upper table in Table 19.

Therefore, the zoom compensation cam (a curve g_(2H) in FIG. 1) is determined by subtracting the focus cam (the curve g₂ in FIG. 1) from the movement locus (the curve g₂ in FIG. 1) upon zooming of the second lens unit determined by the paraxial data in the upper table in Table 19.

FIG. 1 and FIG. 2 will be briefly described below.

FIG. 1 shows the paraxial arrangement and the movement loci upon zooming of the zoom lens according to the first embodiment, and FIG. 1 shows the shapes of the focus cam and the zoom compensation cam of the second lens unit of this embodiment. Referring to FIG. 1, G1, G2, G3, and G4 respectively represent the first, second, third, and fourth lens units, and g₁, g₂, g₃, and g₄ respectively represent the movement loci upon zooming of the first, second, third, and fourth lens units. In addition, g_(2F) and g_(2H) respectively represent the shapes of the focus cam and the zoom compensation cam of the second lens unit. As described above, a shape obtained by synthesizing the focus cam g_(2F) and the zoom compensation cam g_(2H) of the second lens unit coincides with the movement locus g₂ of the second lens unit.

FIG. 2 is a view for explaining the shape of the focus cam _(2F) of the first embodiment. Referring to FIG. 2, (F=28.8; R=un) and (F=28.8; R=0.95) respectively represent the in-focus positions at the infinity and the closest distance (R=0.95 m) at the wide-angle end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(0; 0) and (x; a)=(0.536; -6.5). On the other hand, (F=194; R=un) and (F=194; R=0.95) respectively represent the in-focus positions at the infinity and the closest distance (R=0.95 m) at the telephoto end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(-5.308; 10) and (x; a)=(-0.635; 3.5).

Upon zooming from the wide-angle end to the telephoto end, the second lens unit moves on the focus cam g_(2F) from the coordinate position (0; 0) to the coordinate position (-5.308; 10) for an infinity object, and from the coordinate position (0.536; -6.5) to the coordinate position (-0.635; 3.5) for a closest distance object. Therefore, the second lens unit moves by 10.0 in the direction of rotation (the direction of an axis a) in both the cases. On the other hand, upon focusing from the infinity arrangement to the closest distance object, the second lens unit moves on the focus cam g_(2F) from the coordinate position (0; 0) to the coordinate position (0.536, -6.5) at the wide-angle end, and from the coordinate position (-5.308; 10) to the coordinate position (-0.635; 3.5) at the telephoto end. Therefore, the second lens unit moves by -6.5 in the direction of rotation (the direction of the axis a) at these ends. In contrast to this, in the direction of the optical axis (the direction of an axis x), the second lens unit moves by 0.536 at the wide-angle end, and by 4.673 at the telephoto end.

Since the shape of the focus cam g_(2F) is determined by interpolating the coordinates (F=28.8; R=0.95), (F=28.8; R=un), (F=194; R=0.95), and (F=194; R=un) by the spline function, the change in slope (dx/da) of the focus cam g_(2F) becomes larger as the absolute value of the x-coordinate of (F=28.8; R=0.95) is smaller or as the absolute value of the x-coordinate of (F=194; R=un) is larger. More specifically, as the ratio (Δx_(TR) /Δx_(WR)) between the amounts ΔX_(XR) and ΔX_(WR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end or telephoto end is larger, the change in slope (dx/da) of the focus cam becomes larger.

Tables 21, 22, and 23 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=85.0), and the telephoto end (F=194.0) according to the first embodiment, respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), and 4) on the right side respectively represent the first, second, third, and fourth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(K) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m).

                                      TABLE 21                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End (28.8 mm) in First Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.374                                                                              1)                                                                               .000                                                                               2)                                                                               .048                                                                               3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               .097                                                                               3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               .163                                                                               3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               .247                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               .332                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               .419                                                                               3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               .536                                                                               3)                                                                               .000 4)                                                                               .000                                         Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in First                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.250                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 10.000                                                                             ANG                                                                               -.374                                                                              1)                                                                               -.009                                                                              2)                                                                               -.247                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               -.018                                                                              2)                                                                               -.243                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               -.030                                                                              2)                                                                               -.239                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               -.047                                                                              2)                                                                               -.233                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               -.065                                                                              2)                                                                               -.227                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               -.084                                                                              2)                                                                               -.221                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               -.112                                                                              2)                                                                               -.214                                                                              3)                                                                               -63.758                                                                             4)                                                                               .021                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle                                                             End (28.8 mm) in First Embodiment                                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.722                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.374                                                                              1)                                                                               .000                                                                               2)                                                                               1.725                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               1.728                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               1.732                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               1.737                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               1.741                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               1.746                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.753                                                                              3)                                                                               .000 4)                                                                               .000                                         Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in First Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.132                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.374                                                                              1)                                                                               .000                                                                               2)                                                                               -.126                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               -.118                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               -.106                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               -.093                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               -.079                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.065                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .0u0                                                                               2)                                                                               -.048                                                                              3)                                                                               .000 4)                                                                               .000                                         Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (28.8 mm) in First Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.228                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.374                                                                              1)                                                                               .000                                                                               2)                                                                               -.217                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               -.204                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               -.184                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               -.161                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               -.138                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.114                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.084                                                                              3)                                                                               .000 4)                                                                               .000                                         __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.02,         γ.sub.aR /γ.sub.a0 = 0.37                                    

                                      TABLE 22                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (85.0 mm) in First Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.367                                                                              1)                                                                               .000                                                                               2)                                                                               .152                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.762                                                                              1)                                                                               .000                                                                               2)                                                                               .303                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.341                                                                             1)                                                                               .000                                                                               2)                                                                               .500                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.173                                                                             1)                                                                               .000                                                                               2)                                                                               .743                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.164                                                                             1)                                                                               .000                                                                               2)                                                                               .981                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -4.384                                                                             1)                                                                               .000                                                                               2)                                                                               1.215                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.519                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Middle Position            (85.0 mm) in First Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.419                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 10.000                                                                             ANG                                                                               -.367                                                                              1)                                                                               -.009                                                                              2)                                                                               -.408                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 5.000                                                                              ANG                                                                               -.762                                                                              1)                                                                               -.018                                                                              2)                                                                               -.398                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 3.000                                                                              ANG                                                                               -1.341                                                                             1)                                                                               -.031                                                                              2)                                                                               -.385                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 2.000                                                                              ANG                                                                               -2.173                                                                             1)                                                                               -.048                                                                              2)                                                                               -.368                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 1.500                                                                              ANG                                                                               -3.164                                                                             1)                                                                               -.067                                                                              2)                                                                               -.352                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R 1.200                                                                              ANG                                                                               -4.384                                                                             1)                                                                               -.087                                                                              2)                                                                               -.336                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               -.117                                                                              2)                                                                               -.315                                                                              3)                                                                               5.606                                                                              4)                                                                               -.426                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle                                                                 Position (85.0 mm) in First Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               4.702                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.367                                                                              1)                                                                               .000                                                                               2)                                                                               4.751                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.762                                                                              1)                                                                               .000                                                                               2)                                                                               4.798                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.341                                                                             1)                                                                               .000                                                                               2)                                                                               4.858                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.173                                                                             1)                                                                               .000                                                                               2)                                                                               4.929                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.164                                                                             1)                                                                               .000                                                                               2)                                                                               4.995                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -4.384                                                                             1)                                                                               .000                                                                               2)                                                                               5.058                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               5.135                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Middle Position (85.0 mm) in First                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.434                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.367                                                                              1)                                                                               .000                                                                               2)                                                                               -.398                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.762                                                                              1)                                                                               .000                                                                               2)                                                                               -.364                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.341                                                                             1)                                                                               .000                                                                               2)                                                                               -.319                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.173                                                                             1)                                                                               .000                                                                               2)                                                                               -.266                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.164                                                                             1)                                                                               .000                                                                               2)                                                                               -.217                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -4.384                                                                             1)                                                                               .000                                                                               2)                                                                               -.170                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.123                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position                                                    (85.0 mm) in First Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -2.040                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.367                                                                              1)                                                                               .000                                                                               2)                                                                               -1.889                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.762                                                                              1)                                                                               .000                                                                               2)                                                                               -1.745                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.341                                                                             1)                                                                               .000                                                                               2)                                                                               -1.551                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.173                                                                             1)                                                                               .000                                                                               2)                                                                               -1.310                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.164                                                                             1)                                                                               .000                                                                               2)                                                                               -1.082                                                                             3)                                                                               .000                                                                               4)                                              R 1.200                                                                              ANG                                                                               -4.384                                                                             1)                                                                               .000                                                                               2)                                                                               -.860                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.629                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.09,         γ.sub.aR /γ.sub.a0 = 0.31                                    

                                      TABLE 23                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End (194.0 mm) in First Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000 3)                                                                               .000                                                                               4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.364                                                                              1)                                                                               .000                                                                               2)                                                                               .766 3)                                                                               .000                                                                               4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               1.387                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               2.082                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               2.813                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               3.445                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               4.008                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               4.673                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         Imaging Magnification β.sub.K of Lens Units at Telephoto End (194.0       mm) in First                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.739                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 10.000                                                                             ANG                                                                               -.364                                                                              1)                                                                               -.009                                                                              2)                                                                               -.687                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               -.018                                                                              2)                                                                               -.645                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               -.031                                                                              2)                                                                               -.598                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               -.049                                                                              2)                                                                               -.548                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               -.068                                                                              2)                                                                               -.505                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               -.089                                                                              2)                                                                               -.467                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               -.121                                                                              2)                                                                               -.422                                                                               3)                                                                               4.318                                                                              4)                                                                               -.715                                        Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto                                                              End (194.0 mm) in First Embodiment                                             R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               4.318                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.364                                                                              1)                                                                               .000                                                                               2)                                                                               5.026                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               5.563                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               6.122                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               6.665                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               7.097                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               7.451                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               7.834                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         Slope dx/da of Focus Cam at Telephoto End (194.0 mm) in First Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -2.494                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.364                                                                              1)                                                                               .000                                                                               2)                                                                               -1.763                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               -1.332                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               -1.032                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               -.736                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               -.546                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.399                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.251                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                         Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (194.0 mm) in First Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -10.769                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.364                                                                              1)                                                                               .000                                                                               2)                                                                               -8.863                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.775                                                                              1)                                                                               .000                                                                               2)                                                                               -7.412                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.364                                                                             1)                                                                               .000                                                                               2)                                                                               -6.321                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.208                                                                             1)                                                                               .000                                                                               2)                                                                               -4.908                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.203                                                                             1)                                                                               .000                                                                               2)                                                                               -3.877                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -4.411                                                                             1)                                                                               .000                                                                               2)                                                                               -2.971                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         R .950                                                                               ANG                                                                               -6.500                                                                             1)                                                                               .000                                                                               2)                                                                               -1.968                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                         __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.81,         γ.sub.aR /γ.sub.a0 = 0.18                                    

As can be seen from Tables 21, 22, and 23, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to a case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-open No. 5-142475.

From Tables 21, 22, and 23, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.37 at the wide-angle end (F=28.8), ×0.31 at the middle position (F=85.0), and ×0.18 at the telephoto end (F=194.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the first embodiment is calculated using formula (a), and is compared with that a case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values: when the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0.

    N.sub.W >14.6 N.sub.M >14. 5 N.sub.T >12.3

First Embodiment

    N.sub.W >5.5 N.sub.M >6.5 N.sub.T >9.3

Therefore, as can be understood from a comparison with the case in which the ratio of amounts of rotation (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N of divisions become small.

As described above, in the zoom lens of the first embodiment, since the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation becomes much smaller than that in a case in which the ratio (a_(F) /a_(Z)) of amounts of rotation is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open NO. 5-142475, the number of data of the conversion coefficient μ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 24, 25, and 26 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=28.8), middle position (F=85.0), and telephoto end (F=194.0) according to the first embodiment. In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 mm), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 24, 25, and 26, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and an object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 15, 16, and 17, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.95, -6.5), and it indicates that this position corresponds to the closest in-focus (R=0.95 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=0.95 m) object, and the tenth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.95 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the tenth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.95 m) object to an in-focus state at the object distance in the second column.

As described above, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μ is calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eight row, fourth column in first table: (-0.148) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=0.95 m) in Table 24 is calculated by K_(a) =0.96/-6.5=-0.148 using ΔBf=0.96 and Δa =-6.5. On the other hand, the value of the correction coefficient μ (eight row, fourth column in second table: 2.75) is calculated as μ=2.75 using ΔBf=0.96, K_(a) =-0.148, and γ_(a) =-0.228.

                                      TABLE 24                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (28.8 mm) of First Embodiment          F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.374                                                                              5.000                                                                              -.775                                                                              3.000                                                                              -1.364                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.228                                                                              .000    -.222   -.215   -.205                                       2  10.000  -.224                                                                              -.217                                                                              .000    -.210   -.199                                       3  5.000   -.218   -.211                                                                              -.204                                                                              .000    -.193                                       4  3.000   -.209   -.202   -.195                                                                              -.184                                                                              .000                                        5  2.000   -.197   -.190   -.183   -.173                                       6  1.500   -.184   -.177   -.171   -.161                                       7  1.200   -.169   -.163   -.157   -.149                                       8  .950    -.148   -.143   -.137   -.129                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               3.72                                                                               -.17                                                                               2.99                                                                               -.28                                                                               2.52                                        2  10.000                                                                             .08 4.18                                                                               .00 .00 -.08                                                                               2.76                                                                               -.20                                                                               2.42                                        3  5.000                                                                              .17 3.79                                                                               .08 3.12                                                                               .00 .00 -.11                                                                               2.38                                        4  3.000                                                                              .28 3.39                                                                               .20 2.87                                                                               .11 2.53                                                                               .00 .00                                         5  2.000                                                                              .43 3.15                                                                               .35 2.77                                                                               .26 2.54                                                                               .15 2.42                                        6  1.500                                                                              .59 3.01                                                                               .50 2.72                                                                               .41 2.53                                                                               .30 2.40                                        7  1.200                                                                              .75 2.90                                                                               .66 2.65                                                                               .57 2.48                                                                               .45 2.33                                        8  .950                                                                               .96 2.75                                                                               .87 2.55                                                                               .79 2.40                                                                               .67 2.24                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.208                                                                             1.500                                                                              -3.203                                                                             1.200                                                                              -4.411                                                                             .950                                                                               -6.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.191   -.176   -.161   -.139                                       2  10.000  -.185   -.171   -.156   -.134                                       3  5.000   -.179   -.166   -.151   -.130                                       4  3.000   -.171   -.158   -.144   -.124                                       5  2.000                                                                              -.161                                                                              .000    -.148   -.135   -.115                                       6  1.500   -.150                                                                              -.138                                                                              .000    -.125   -.107                                       7  1.200   -.138   -.126                                                                              -.114                                                                              .000    -.097                                       8  .950    -.120   -.109   -.099                                                                              -.084                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.42                                                                               2.28                                                                               -.56                                                                               2.02                                                                               -.71                                                                               1.72                                                                               -.90                                                                               1.39                                        2  10.000                                                                             -.34                                                                               2.25                                                                               -.48                                                                               2.00                                                                               -.63                                                                               1.70                                                                               -.82                                                                               1.38                                        3  5.000                                                                              -.26                                                                               2.24                                                                               -.40                                                                               1.99                                                                               -.55                                                                               1.69                                                                               -.74                                                                               1.37                                        4  3.000                                                                              -.14                                                                               2.24                                                                               -.29                                                                               1.97                                                                               -.44                                                                               1.66                                                                               -.63                                                                               1.36                                        5  2.000                                                                              .00 .00 -.15                                                                               1.91                                                                               -.30                                                                               1.62                                                                               -.50                                                                               1.34                                        6  1.500                                                                              .15 2.18                                                                               .00 .00 -.15                                                                               1.57                                                                               -.35                                                                               1.32                                        7  1.200                                                                              .30 2.09                                                                               .15 1.81                                                                               .00 .00 -.20                                                                               1.32                                        8  .950                                                                               .51 2.00                                                                               .36 1.75                                                                               .21 1.53                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.65, K.sub.aR      /γ.sub.aR = 1.65                                                   

                                      TABLE 25                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (85.0 mm) of First Embodiment         F = 85.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.367                                                                              5.000                                                                              -.762                                                                              3.000                                                                              -1.341                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -2.040                                                                             .000    -1.932  -1.830  -1.695                                      2  10.000  -1.994                                                                             -1.888                                                                             .000    -1.789  -1.656                                      3  5.000   -1.948  -1.845                                                                             -1.745                                                                             .000    -1.613                                      4  3.000   -1.880  -1.779  -1.681                                                                             -1.551                                                                             .000                                        5  2.000   -1.783  -1.685  -1.589  -1.463                                      6  1.500   -1.673  -1.579  -1.487  -1.367                                      7  1.200   -1.547  -1.458  -1.371  -1.258                                      8  .950    -1.364  -1.283  -1.204  -1.103                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.71                                                                               30.55                                                                              -1.39                                                                              28.77                                                                              -2.27                                                                              24.40                                       2  10.000                                                                             .73 32.17                                                                              .00 .00 -.71                                                                               28.19                                                                              -1.61                                                                              23.81                                       3  5.000                                                                              1.49                                                                               32.70                                                                              .73 32.06                                                                              .00 .00 -.93                                                                               23.15                                       4  3.000                                                                              2.52                                                                               32.07                                                                              1.73                                                                               30.01                                                                              .97 26.33                                                                              .00 .00                                         5  2.000                                                                              3.87                                                                               30.69                                                                              3.04                                                                               28.23                                                                              2.24                                                                               25.02                                                                              1.22                                                                               21.51                                       6  1.500                                                                              5.29                                                                               29.39                                                                              4.41                                                                               26.93                                                                              3.57                                                                               24.11                                                                              2.49                                                                               21.01                                       7  1.209                                                                              6.78                                                                               28.07                                                                              5.86                                                                               25.69                                                                              4.96                                                                               23.15                                                                              3.83                                                                               20.26                                       8  .950                                                                               8.86                                                                               26.72                                                                              7.87                                                                               24.52                                                                              6.91                                                                               22.28                                                                              5.69                                                                               19.69                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.173                                                                             1.500                                                                              -3.164                                                                             1.200                                                                              -4.384                                                                             .950                                                                               -6.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -1.529  -1.365  -1.203  -.995                                       2  10.000  -1.491  -1.330  -1.170  -.966                                       3  5.000   -1.451  -1.292  -1.135  -.936                                       4  3.000   -1.392  -1.238  -1.085  -.893                                       5  2.000                                                                              -1.310                                                                             .000    -1.164  -1.017  -.836                                       6  1.500   -1.222                                                                             -1.082                                                                             .000    -.943   -.774                                       7  1.200   -1.122  -.989                                                                              -.860                                                                              .000    -.709                                       8  .950    -.981   -.865   -.755                                                                              -.629                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -3.32                                                                              19.86                                                                              -4.32                                                                              16.47                                                                              -5.27                                                                              13.23                                                                              -6.46                                                                              11.13                                       2  10.000                                                                             -2.69                                                                              19.45                                                                              -3.72                                                                              16.21                                                                              -4.70                                                                              13.04                                                                              -5.92                                                                              11.06                                       3  5.000                                                                              -2.05                                                                              19.03                                                                              -3.10                                                                              15.96                                                                              -4.11                                                                              12.86                                                                              -5.37                                                                              11.01                                       4  3.000                                                                              -1.16                                                                              18.54                                                                              -2.26                                                                              15.65                                                                              -3.30                                                                              12.62                                                                              -4.61                                                                              10.98                                       5  2.000                                                                              .00 .00 -1.15                                                                              15.21                                                                              -2.25                                                                              12.29                                                                              -3.62                                                                              11.00                                       6  1.500                                                                              1.21                                                                               18.15                                                                              .00 .00 -1.15                                                                              11.96                                                                              -2.58                                                                              11.20                                       7  1.200                                                                              2.48                                                                               17.28                                                                              1.21                                                                               14.14                                                                              .00 .00 -1.50                                                                              11.76                                       8  .950                                                                               4.25                                                                               16.93                                                                              2.89                                                                               14.41                                                                              1.60                                                                               13.13                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.67, K.sub.aR      /γ.sub.aR = 1.58                                                   

                                      TABLE 26                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (194.0 mm) of First Embodiment          F = 194.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.364                                                                              5.000                                                                              -.775                                                                              3.000                                                                              -1.364                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -10.773                                                                            .000    -9.087  -7.713  -6.525                                      2  10.000  -10.709                                                                            -8.864                                                                             .000    -7.498  -6.402                                      3  5.000   -10.460 -8.614                                                                             -7.414                                                                             .000    -6.382                                      4  3.000   -10.442 -8.650  -7.494                                                                             -6.325                                                                             .000                                        5  2.000   -10.378 -8.548  -7.324  -6.075                                      6  1.500   -10.286 -8.395  -7.128  -5.874                                      7  1.200   -10.127 -8.171  -6.873  -5.617                                      8  .950    -9.771  -7.736  -6.416  -5.177                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -3.31                                                                              131.41                                                                             -5.98                                                                              148.50                                                                             -8.90                                                                              281.64                                      2  10.000                                                                             3.90                                                                               656.67                                                                             .00 .00 -3.08                                                                              273.04                                                                             -6.40                                                                              526.44                                      3  5.000                                                                              8.11                                                                               278.71                                                                             3.54                                                                               125.86                                                                             .00 .00 -3.76                                                                              419.92                                      4  3.000                                                                              14.24                                                                              463.41                                                                             8.65                                                                               358.25                                                                             4.41                                                                               -412.24                                                                            .00 .00                                         5  2.000                                                                              22.91                                                                              625.46                                                                             15.76                                                                              442.35                                                                             10.49                                                                              858.42                                                                             5.13                                                                               129.63                                      6  1.500                                                                              32.94                                                                              727.96                                                                             23.83                                                                              450.74                                                                             17.30                                                                              448.54                                                                             10.80                                                                              151.32                                      7  1.200                                                                              44.67                                                                              745.50                                                                             33.06                                                                              423.26                                                                             24.99                                                                              342.21                                                                             17.11                                                                              152.80                                      8  .950                                                                               63.51                                                                              683.20                                                                             47.46                                                                              373.00                                                                             36.73                                                                              272.88                                                                             26.59                                                                              146.51                                      __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.208                                                                             1.500                                                                              -3.203                                                                             1.200                                                                              -4.411                                                                             .950                                                                               -6.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -5.384  -4.488  -3.743  -2.913                                      2  10.000  -5.285  -4.402  -3.666  -2.847                                      3  5.000   -5.228  -4.336  -3.600  -2.785                                      4  3.000   -5.102  -4.219  -3.491  -2.690                                      5  2.000                                                                              -4.907                                                                             .000    -4.060  -3.343  -2.561                                      6  1.500   -4.738                                                                             -3.876                                                                             .000    -3.169  -2.413                                      7  1.200   -4.493  -3.645                                                                             -2.969                                                                             .000    -2.246                                      8  .950    -4.091  -3.288  -2.656                                                                             -1.967                                                                             .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -11.89                                                                             122.19                                                                             -14.37                                                                             90.97                                                                              -16.51                                                                             63.35                                                                              -18.93                                                                             39.37                                       2  10.000                                                                             -9.74                                                                              126.26                                                                             -12.49                                                                             92.01                                                                              -14.83                                                                             63.20                                                                              -17.47                                                                             39.04                                       3  5.000                                                                              -7.49                                                                              114.37                                                                             -10.53                                                                             88.60                                                                              -13.09                                                                             61.65                                                                              -15.95                                                                             38.32                                       4  3.000                                                                              -4.31                                                                              107.94                                                                             -7.76                                                                              87.53                                                                              -10.64                                                                             60.51                                                                              -13.82                                                                             37.56                                       5  2.000                                                                              .00 .00 -4.04                                                                              84.82                                                                              -7.36                                                                              58.59                                                                              -10.99                                                                             36.4l                                       6  1.500                                                                              4.71                                                                               137.55                                                                             .00 .00 -3.83                                                                              56.96                                                                              -7.96                                                                              35.09                                       7  1.200                                                                              9.90                                                                               117.35                                                                             4.40                                                                               73.94                                                                              .00 .00 -4.69                                                                              33.10                                       8  .950                                                                               17.56                                                                              105.60                                                                             10.84                                                                              71.42                                                                              5.55                                                                               52.59                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.91 K.sub.aR       /γ.sub.aR = 1.48                                                   

As can be seen from Tables 24, 25, and 26 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) is considered, the rate of change becomes small as compared to the change in K_(a) (Tables 6, 7, and 8) in a case in which the ratio (a_(F) /a_(Z)) of amounts of rotation is set to be 1.0, as in the previously-discussed embodiment of Japanese Patent Application Laid-Open No. 5-142475 examined previously.

More specifically, the amount Δa of rotation for focusing in the first embodiment at the infinity object side becomes relatively smaller than that at the closest object side, as compared to a case in which the ratio (a_(F) /a_(Z)) of amounts of rotation is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475. In fact, when the ratio between the amount of rotation for focusing upon focusing to the closest distance and the amount of rotation for focusing upon focusing to the object distance (R=5.0 m) is calculated in Tables 1 and 19, 4.807/10.0=0.481 when the ratio (a_(F) /a_(Z)) of amounts of rotation is set to be 1.0, while -0.775/-6.5=0.119 in the first embodiment. As described above, when the focus cam with the arrangement of the present invention is used, since the amount Δa of rotation for focusing becomes relatively smaller at the infinity object side, the conversion coefficient K_(a) becomes relatively large at the infinity object side, and consequently, the change in conversion coefficient K_(a) in the direction of rotation can be reduced as compared to the conventional system.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end (F=28.8), middle position (F=85.0), and telephoto end (F=194.0) in the case in which the ratio (a_(F) /a_(Z)) of amounts of rotation is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the first embodiment of the present invention is which said ratio (a_(F) /a_(Z)) is set to be -0.65 are as follows.

    ______________________________________                                         When the ratio (a.sub.F /a.sub.Z) is set to be 1.0                                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            5.05           0.33                                                 (F = 28.8)                                                                     Middle Position                                                                           6.24           0.32                                                 (F = 85.0)                                                                     Telephoto End                                                                             9.49           0.30                                                 (F = 194.0)                                                                    First Embodiment                                                               Wide-angle End                                                                            0.65           1.65                                                 (F = 28.8)                                                                     Middle Position                                                                           0.67           1.58                                                 (F = 85.0)                                                                     Telephoto End                                                                             0.91           1.48                                                 (F = 194.0)                                                                    ______________________________________                                    

As described above, according to the present invention, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, and the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced, the value of the correction coefficient μ can be set to be large as compared to the defocus amount ΔBf, and at the same time, the change in correction coefficient μ can be decreased.

Therefore, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement large, an error in the conversion coefficient K_(a) calculated using γ_(a) and μ or in the actual lens driving amount Δa for focusing can be eliminated.

Next, in the case in which the ratio (a_(F) /a_(Z)) of amounts of rotation is set to 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the first embodiment of the present invention in which the ratio (a_(F) /a_(Z)) is set to -0.65, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end (F=28.8), middle position (F=85.0), and telephoto end (F=194.0) are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the ratio (a.sub.F /a.sub.Z) of amounts of rotation is set to 1.0                  Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -9.3%         -27.2%                                               (F = 28.8)                                                                     Middle Position                                                                           -11.7%         -28.3%                                               (F = 85.0)                                                                     Telephoto End                                                                             -13.7%         -28.9%                                               (F = 194.0)                                                                    First Embodiment                                                               Wide-angle End                                                                             -6.8%         -0.8%                                                (F = 28.8)                                                                     Middle Position                                                                           -6.1%          -0.5%                                                (F = 85.0)                                                                     Telephoto End                                                                             1.0%           -1.6%                                                (F = 194.0)                                                                    ______________________________________                                    

As described above, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Next, an examination will be made as to whether not only accurate auto-focusing but also so-called manual focusing can be attained in the zoom lens of the first embodiment.

Table 27 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 19) of the first embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 27 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m). Note that the amounts of rotation for focusing, which have values for eliminating any displacement of the imaging point at the wide-angle end and the telephoto end, are selected. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) in the respective zooming states with the focal lengths (F=28.8, 35.0, 50.0, 85.0, 135.0, and 194.0 mm). In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, and fourth lens units in turn from the right side. Note that the amount of movement in the direction of the optical axis toward the object side is represented by a positive value.

                                      TABLE 27                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount                        DX (mm) of movement for focusing in First Embodiment                           __________________________________________________________________________             0.95 m                                                                             1.20 m                                                                               1.50 m                                                                             2.00 m                                                                               3.00 m                                                                             5.00 m                                         __________________________________________________________________________     F 28.800 Bf                                                                            .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           F 35.000 Bf                                                                            .000                                                                               .001  .002                                                                               .003  .006                                                                               .006                                           F 50.000 Bf                                                                            .000                                                                               .007  .016                                                                               .015  .007                                                                               .002                                           F 85.000 Bf                                                                            .000                                                                               -.023 -.042                                                                              -.046 -.035                                                                              -.022                                          F 135.000 Bf                                                                           .000                                                                               -.043 -.038                                                                              -.042 -.027                                                                              -.019                                          F 194.000 Bf                                                                           .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           __________________________________________________________________________       ANGLE DA                                                                             -6.500                                                                              -4.411                                                                             -3.203                                                                              -2.208 -1.364                                                                             -.775                                         __________________________________________________________________________     F 28.800 DX                                                                            .000 .536                                                                               .000 .000                                                                               R  0.95 m                                            F 35.000 DX                                                                            .000 .622                                                                               .000 .000                                                                               R  0.95 m                                            F 50.000 DX                                                                            .000 .855                                                                               .000 .000                                                                               R  0.95 m                                            F 85.000 DX                                                                            .000 1.519                                                                              .000 .000                                                                               R  0.95 m                                            F 135.000 DX                                                                           .000 2.800                                                                              .000 .000                                                                               R  0.95 m                                            F 194.000 DX                                                                           .000 4.673                                                                              .000 .000                                                                               R  0.95 m                                            F 28.800 DX                                                                            .000 .419                                                                               .000 .000                                                                               R  1.20 m                                            F 35.000 DX                                                                            .000 .487                                                                               .000 .000                                                                               R  1.20 m                                            F 50.000 DX                                                                            .000 .671                                                                               .000 .000                                                                               R  1.20 m                                            F 85.000 DX                                                                            .000 1.220                                                                              .000 .000                                                                               R  1.20 m                                            F 135.000 DX                                                                           .000 2.315                                                                              .000 .000                                                                               R  1.20 m                                            F 194.000 DX                                                                           .000 4.008                                                                              .000 .000                                                                               R  1.20 m                                            F 28.800 DX                                                                            .000 .332                                                                               .000 .000                                                                               R  1.50 m                                            F 35.000 DX                                                                            .000 .386                                                                               .000 .000                                                                               R  1.50 m                                            F 50.000 DX                                                                            .000 .532                                                                               .000 .000                                                                               R  1.50 m                                            F 85.000 DX                                                                            .000 .989                                                                               .000 .000                                                                               R  1.50 m                                            F 135.000 DX                                                                           .000 1.918                                                                              .000 .000                                                                               R  1.50 m                                            F 194.000 DX                                                                           .000 3.445                                                                              .000 .000                                                                               R  1.50 m                                            F 28.800 DX                                                                            .000 .247                                                                               .000 .000                                                                               R  2.00 m                                            F 35.000 DX                                                                            .000 .286                                                                               .000 .000                                                                               R  2.00 m                                            F 50.000 DX                                                                            .000 .397                                                                               .000 .000                                                                               R  2.00 m                                            F 85.000 DX                                                                            .000 .752                                                                               .000 .000                                                                               R  2.00 m                                            F 135.000 DX                                                                           .000 1.497                                                                              .000 .000                                                                               R  2.00 m                                            F 194.000 DX                                                                           .000 2.813                                                                              .000 .000                                                                               R  2.00 m                                            F 28.800 DX                                                                            .000 .163                                                                               .000 .000                                                                               R  3.00 m                                            F 35.000 DX                                                                            .000 .188                                                                               .000 .000                                                                               R  3.00 m                                            F 50.000 DX                                                                            .000 .264                                                                               .000 .000                                                                               R  3.00 m                                            F 85.000 DX                                                                            .000 .507                                                                               .000 .000                                                                               R  3.00 m                                            F 135.000 DX                                                                           .000 1.042                                                                              .000 .000                                                                               R  3.00 m                                            F 194.000 DX                                                                           .000 2.082                                                                              .000 .000                                                                               R  3.00 m                                            F 28.800 DX                                                                            .000 .097                                                                               .000 .000                                                                               R  5.00 m                                            F 35.000 DX                                                                            .000 .111                                                                               .000 .000                                                                               R  5.00 m                                            F 50.000 DX                                                                            .000 .159                                                                               .000 .000                                                                               R  5.00 m                                            F 85.000 DX                                                                            .000 .307                                                                               .000 .000                                                                               R  5.00 m                                            F 135.000 DX                                                                           .000 .651                                                                               .000 .000                                                                               R  5.00 m                                            F 194.000 DX                                                                           .000 1.387                                                                              .000 .000                                                                               R  5.00 m                                            __________________________________________________________________________

As can be seen from Table 27, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Second Embodiment!

The second embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.8 m) to the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=131.0) is set to be -0.75.

Table 28 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the second embodiment.

The upper table in Table 28 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the second embodiment in association with six zooming states (focal length F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 70.0 (4-POS), 105.0 (5-POS) and 131.0 mm (6-POS)).

The middle table in Table 28 summarizes spline sample data when the shape of the focus cam in the second lens unit of the second embodiment, which is used for focusing, is expressed by a spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 28 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=28.8, 35.0, 50.0, 70.0, 105.0, and 131.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) using the focus cam of the second embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=131.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.8 m) is set to be -7.5, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the second embodiment is -0.75.

                                      TABLE 28                                     __________________________________________________________________________     Second Embodiment F = 28.8 to 131.0 (Rotation Amount Ratio: a.sub.F            /a.sub.Z = -0.75)                                                              __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Second            Embodiment                                                                              1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                               6-POS                                          __________________________________________________________________________            F 28.8000                                                                            35.0000                                                                             50.0000                                                                            70.0000                                                                             105.0000                                                                            131.0000                                       F1                                                                               77.2000                                                                             D1                                                                               10.3313                                                                            15.1893                                                                             23.5104                                                                            30.7072                                                                             38.5116                                                                             42.3545                                        F2                                                                               -14.7000                                                                            D2                                                                               27.6049                                                                            24.9667                                                                             20.7775                                                                            17.3207                                                                             13.3359                                                                             11.0136                                        F3                                                                               21.3000                                                                             D3                                                                               6.0146                                                                             7.0237                                                                              8.9018                                                                             10.6018                                                                             12.3379                                                                             13.0291                                        F4                                                                               -37.0000                                                                            D4                                                                               9.0353                                                                             8.0262                                                                              6.1481                                                                             4.4481                                                                              2.7120                                                                              2.0208                                         F5                                                                               60.0000                                                                             D5                                                                               50.6898                                                                            52.5061                                                                             55.8867                                                                            58.9468                                                                             62.0719                                                                             63.3160                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding to           Second                                                                         Embodiment                                                                          ANGLE                                                                               (1)    (2) (3)    (4)                                                                               (5)                                             __________________________________________________________________________     1    -10.0000                                                                            .0000  .8070                                                                              .0000  .0000                                                                             .0000                                           2    -7.5000                                                                             .0000  .6835                                                                              .0000  .0000                                                                             .0000                                           3    -5.1843                                                                             .0000  .5397                                                                              .0000  .0000                                                                             .0000                                           4    -2.9523                                                                             .0000  .3538                                                                              .0000  .0000                                                                             .0000                                           5    -2.0697                                                                             .0000  .2632                                                                              .0000  .0000                                                                             .0000                                           6    -1.2981                                                                             .0000  .1740                                                                              .0000  .0000                                                                             .0000                                           7    -.7436                                                                              .0000  .1038                                                                              .0000  .0000                                                                             .0000                                           8    -.0000                                                                              .0000  .0000                                                                              .0000  .0000                                                                             .0000                                           9    2.5000                                                                              .0000  -.4452                                                                             .0000  .0000                                                                             .0000                                           10   4.8157                                                                              .0000  -1.0711                                                                            .0000  .0000                                                                             .0000                                           11   7.0477                                                                              .0000  -2.0300                                                                            .0000  .0000                                                                             .0000                                           12   7.9303                                                                              .0000  -2.5880                                                                            .0000  .0000                                                                             .0000                                           13   8.7019                                                                              .0000  -3.2255                                                                            .0000  .0000                                                                             .0000                                           14   9.2564                                                                              .0000  -3.8190                                                                            .0000  .0000                                                                             .0000                                           15   10.0000                                                                             .0000  -4.9504                                                                            .0000  .0000                                                                             .0000                                           16   11.0000                                                                             .0000  -7.4500                                                                            .0000  .0000                                                                             .0000                                           __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Second Embodiment                                                              Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.75)                               __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     28.8 mm        .0000  5.00 m    -.744                                          35.0 mm        1.4190                                                                                3.00 m    -1.298                                         50.0 mm        3.9887                                                                                2.00 m    -2.070                                         70.0 mm        6.3656                                                                                1.50 m    -2.952                                         105.0 mm       8.9103                                                                                1.00 m    -5.184                                         131.0 mm       10.0000                                                                               0.80 m    -7.500                                         Condition Corresponding Value (1)                                                                    1.76                                                     Condition Corresponding Value (2)                                                                    6.59                                                     Condition Corresponding Value (3)                                                                   -0.75                                                     Condition Corresponding Value (4)                                                                    0.38 (wide-angle end)                                                          0.19 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.65 (wide-angle end)                                                          0.79 (telephoto end)                                     Condition Corresponding Value (6)                                                                    1.59 (wide-angle end)                                                          1.52 (telephoto end)                                     __________________________________________________________________________

Table 29 below summarizes the numerical value data of the cams of the focusing lens unit in the second embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 28. Note that the meanings of the reference symbols in Table 29 are the same as those in the first embodiment.

                  TABLE 29                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Second                       Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)       F        ANGLE  (2)    F                                      ______________________________________                                         -7.5000                                                                               .6835     .0000                                                         -7.0000                                                                               .6557     .0000                                                         -6.5000                                                                               .6263     .0000                                                         -6.0000                                                                               .5951     .0000                                                         -5.5000                                                                               .5618     .0000                                                         -5.0000                                                                               .5264     .0000                                                         -4.5000                                                                               .4885     .0000                                                         -4.0000                                                                               .4480     .0000                                                         -3.5000                                                                               .4047     .0000                                                         -3.0000                                                                               .3584     .0000                                                         -2.5000                                                                               .3088     .0000                                                         -2.0000                                                                               .2555     .0000                                                         -1.5000                                                                               .1983     .0000                                                         -1.0000                                                                               .1370     .0000                                                         -.5000 .0710     .0000                                                         .0000  .0000     28.8000  .0000  .0000  28.8000                                .5000  -.0759    30.8560  .5000  .2539  30.8560                                1.0000 -.1573    33.0458  1.0000 -.4569 33.0458                                1.5000 -.2454    35.3916  1.5000 -.6163 35.3916                                2.0000 -.3410    37.9133  2.0000 -.7276 37.9133                                2.5000 -.4452    40.6272  2.5000 -.8018 40.6272                                3.0000 -.5589    43.5482  3.0000 -.8388 43.5482                                3.5000 -.6834    46.6939  3.5000 -.8415 46.6939                                4.0000 -.8198    50.0790  4.0000 -.8129 50.0790                                4.5000 -.9694    53.7142  4.5000 -.7562 53.7142                                5.0000 -1.1334   57.6059  5.0000 -.6746 57.6059                                5.5000 -1.3144   61.7941  5.5000 -.5712 61.7941                                6.0000 -1.5167   66.3669  6.0000 -.4479 66.3669                                6.5000 -1.7450   71.4029  6.5000 -.3068 71.4029                                7.0000 -2.0036   76.9473  7.0000 -.1503 76.9473                                7.5000 -2.2981   83.0582  7.5000 .0186  83.0582                                8.0000 -2.6387   89.9025  8.0000 .1978  89.9025                                8.5000 -3.0406   97.6869  8.5000 .3859  97.6869                                9.0000 -3.5275   106.7265 9.0000 .5812  106.7265                               9.5000 -4.1299   117.3403 9.5000 .7803  117.3403                               10.0000                                                                               -4.9504   131.0000 10.0000                                                                               .9852  131.0000                               ______________________________________                                    

The left table in Table 29 summarizes the numerical value data of the focus cam of the second embodiment, and the right table in Table 29 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 28.

Tables 30, 31, and 32 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=70.0), and the telephoto end (F=131.0) according to the second embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 30                                     __________________________________________________________________________     Amount DX (min) of Movement for Focusing in Direction of Optical Axis at       Wide-angle                                                                     End (28.8 mm) in Second Embodiment                                             R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.360                                                                              1)                                                                               .000                                                                               2)                                                                               .052                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               .104                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               .174                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               .263                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               .354                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               .540                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               .684                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in Second                                                                  Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.282                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 10.000                                                                             ANG                                                                               -.360                                                                              1)                                                                               -.008                                                                              2)                                                                               -.278                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               -.016                                                                              2)                                                                               -.275                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               -.027                                                                              2)                                                                               -.270                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               -.042                                                                              2)                                                                               -.264                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               -.059                                                                              2)                                                                               -.258                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               -.094                                                                              2)                                                                               -.245                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               -.125                                                                              2)                                                                               -.235                                                                              3)                                                                               -.847                                                                              4)                                                                               10.073                                                                             5)                                                                               .155                                    Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle End                                                         (28.8 mm) in Second Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.614                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.360                                                                              1)                                                                               .000                                                                               2)                                                                               1.617                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               1.621                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               1.625                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               1.631                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               1.636                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               1.648                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.656                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in Second                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.147                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.360                                                                              1)                                                                               .000                                                                               2)                                                                               -.140                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               -.132                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               -.122                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               -.109                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               -.096                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               -.071                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.054                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (28.8 mm) in Second Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.237                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.360                                                                              1)                                                                               .000                                                                               2)                                                                               -.226                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               -.214                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               -.198                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               -.178                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               -.158                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               -.118                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.090                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.03,         γ.sub.aR /γ.sub.a0 = 0.38                                    

                                      TABLE 31                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (70.0 mm) in Second Embodiment                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.357                                                                              1)                                                                               .000                                                                               2)                                                                               .160                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.740                                                                              1)                                                                               .000                                                                               2)                                                                               .318                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.295                                                                             1)                                                                               .000                                                                               2)                                                                               .523                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.068                                                                             1)                                                                               .000                                                                               2)                                                                               .774                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.945                                                                             1)                                                                               .000                                                                               2)                                                                               1.018                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.176                                                                             1)                                                                               .000                                                                               2)                                                                               1.491                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.835                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Middle Position (70.0      mm) in Second                                                                  Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.462                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 10.000                                                                             ANG                                                                               -.357                                                                              1)                                                                               -.008                                                                              2)                                                                               -.451                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 5.000                                                                              ANG                                                                               -.740                                                                              1)                                                                               -.016                                                                              2)                                                                               -.441                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 3.000                                                                              ANG                                                                               -1.295                                                                             1)                                                                               -.028                                                                              2)                                                                               -.427                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 2.000                                                                              ANG                                                                               -2.068                                                                             1)                                                                               -.043                                                                              2)                                                                               -.410                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 1.500                                                                              ANG                                                                               -2.945                                                                             1)                                                                               -.059                                                                              2)                                                                               -.393                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R 1.000                                                                              ANG                                                                               -5.176                                                                             1)                                                                               -.096                                                                              2)                                                                               -.361                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               -.129                                                                              2)                                                                               -.338                                                                              3)                                                                               1.216                                                                              4)                                                                               91.883                                                                             5)                                                                               .018                                    Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle Position                                                        (70.0 mm) in Second Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               3.024                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.357                                                                              1)                                                                               .000                                                                               2)                                                                               3.062                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.740                                                                              1)                                                                               .000                                                                               2)                                                                               3.099                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.295                                                                             1)                                                                               .000                                                                               2)                                                                               3.145                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.068                                                                             1)                                                                               .000                                                                               2)                                                                               3.200                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.945                                                                             1)                                                                               .000                                                                               2)                                                                               3.251                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.176                                                                             1)                                                                               .000                                                                               2)                                                                               3.345                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               3.408                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Slope dx/da of Focus Cam at Middle Position (70.0 mm) in Second                Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.469                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.357                                                                              1)                                                                               .000                                                                               2)                                                                               -.430                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.740                                                                              1)                                                                               .000                                                                               2)                                                                               -.393                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.295                                                                             1)                                                                               .000                                                                               2)                                                                               -.348                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.068                                                                             1)                                                                               .000                                                                               2)                                                                               -.302                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.945                                                                             1)                                                                               .000                                                                               2)                                                                               -.257                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.176                                                                             1)                                                                               .000                                                                               2)                                                                               -.174                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.125                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position (70.0                                              mm) in Second Embodiment                                                       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -1.419                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.357                                                                              1)                                                                               .000                                                                               2)                                                                               -1.317                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.740                                                                              1)                                                                               .000                                                                               2)                                                                               -1.217                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.295                                                                             1)                                                                               .000                                                                               2)                                                                               -1.096                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.068                                                                             1)                                                                               .000                                                                               2)                                                                               -.966                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.945                                                                             1)                                                                               .000                                                                               2)                                                                               -.835                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.176                                                                             1)                                                                               .000                                                                               2)                                                                               -.583                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.424                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.13,         γ.sub.aR /γ.sub.a0 = 0.30                                    

                                      TABLE 32                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End                                                                  (131.0 mm) in Second Embodiment                                                R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.356                                                                              1)                                                                               .000                                                                               2)                                                                               .614                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               1.131                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               1.725                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               2.362                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               2.920                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               3.879                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               4.505                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Telepboto End (131.0       mm) in Second Embodiment                                                       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.730                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 10.000                                                                             ANG                                                                               -.356                                                                              1)                                                                               -.008                                                                              2)                                                                               -.688                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               -.016                                                                              2)                                                                               -.653                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               -.028                                                                              2)                                                                               -.612                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               -.043                                                                              2)                                                                               -.569                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               -.060                                                                              2)                                                                               -.531                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               -.098                                                                              2)                                                                               -.466                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               -.131                                                                              2)                                                                               -.423                                                                              3)                                                                               -1.407                                                                             4)                                                                               -29.909                                                                            5)                                                                               -.055                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto End                                                          (131.0 mm) in Second Embodiment                                                R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               2.528                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.356                                                                              1)                                                                               .000                                                                               2)                                                                               2.848                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               .5)                                                                              .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               3.104                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               3.380                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               3.657                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               3.883                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               4.235                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               4.439                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Slope dx/da of Focus Cam at Telephoto End (131.0 mm) in Second                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -1.975                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.356                                                                              1)                                                                               .000                                                                               2)                                                                               -1.505                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               -1.200                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               -.953                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               -.719                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               -.557                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               -.332                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.218                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (131.0 mm) in Second Embodiment                                                R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -4.993                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.356                                                                              1)                                                                               .000                                                                               2)                                                                               -4.288                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.744                                                                              1)                                                                               .000                                                                               2)                                                                               -3.724                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -1.298                                                                             1)                                                                               .000                                                                               2)                                                                               -3.221                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -2.070                                                                             1)                                                                               .000                                                                               2)                                                                               -2.631                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -2.952                                                                             1)                                                                               .000                                                                               2)                                                                               -2.164                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -5.184                                                                             1)                                                                               .000                                                                               2)                                                                               -1.405                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -7.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.966                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.76,         γ.sub.aR /γ.sub.a0 = 0.19                                    

As can be seen from Tables 30, 31, and 32, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

From Tables 30, 31, and 32, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.38 at the wide-angle end (F=28.8), ×0.30 at the middle position (F=70.0), and ×0.19 at the telephoto end (F=131.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the second embodiment is calculated using formula (a), and is compared with that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values: When the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0

    N.sub.W >13.0N.sub.M >12. 6N.sub.T >10.7

Second Embodiment

    N.sub.W >5.3N.sub.M >6.6N.sub.T >9.0

Therefore, it can be seen that the values of the numbers N of divisions become small, compared to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

As described above, in the second embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is smaller than that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 33, 34, and 35 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=28.8), middle position (F=70.0), and telephoto end (F=131.0) according to the second embodiment.

The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 33, 34, and 35, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 33, 34, and 35, i.e., in the ninth and 10th columns is (R, ANGLE)=(0.8, -7.5), and it indicates that this position corresponds to the closest in-focus (R=0.8 m) corresponding position.

                                      TABLE 33                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (28.8 mm) of Second Embodiment         F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE ) =                                                                         .000                                                                               .000                                                                               10.000                                                                             -.360                                                                              5.000                                                                              -.744                                                                              3.000                                                                              -1.298                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.237                                                                              .000    -.231   -.224   -.215                                       2  10.000  -.232                                                                              -.226                                                                              .000    -.219   -.210                                       3  5.000   -.227   -.221                                                                              -.214                                                                              .000    -.205                                       4  3.000   -.219   -.213   -.207                                                                              -.198                                                                              .000                                        5  2.000   -.210   -.204   -.197   -.189                                       6  1.500   -.199   -.193   -.187   -.179                                       7  1.000   -.176   -.170   -.165   -.157                                       8  .800    -.155   -.151   -.146   -.139                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               4.03                                                                               -.17                                                                               3.50                                                                               -.28                                                                               3.26                                        2  10.000                                                                             .08 4.39                                                                               .00 .00 -.08                                                                               3.31                                                                               -.20                                                                               3.22                                        3  5.000                                                                              .17 4.15                                                                               .08 3.66                                                                               .00 .00 -.11                                                                               3.26                                        4  3.000                                                                              .28 3.91                                                                               .20 3.50                                                                               .11 3.29                                                                               .00 .00                                         5  2.000                                                                              .43 3.80                                                                               .35 3.50                                                                               .26 3.36                                                                               .15 3.27                                        6  1.500                                                                              .59 3.69                                                                               .50 3.44                                                                               .41 3.30                                                                               .30 3.13                                        7  1.000                                                                              .91 3.52                                                                               .82 3.32                                                                               .73 3.18                                                                               .61 3.00                                        8  .800                                                                               1.17                                                                               3.40                                                                               1.08                                                                               3.22                                                                               .98 3.09                                                                               .86 2.90                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.070                                                                             1.500                                                                              -2.952                                                                             1.000                                                                              -5.184                                                                             .800                                                                               -7.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.203   .191    -.164   -.143                                       2  10.000  -.198   .186    -.160   -.139                                       3  5.000   -.193   .182    -.156   -.136                                       4  3.000   -.187   .175    -.151   -.131                                       5  2.000                                                                              -.178                                                                              .000    .167    -.143   -.124                                       6  1.500   -.169                                                                              -.158                                                                              .000    -.135   -.117                                       7  1.000   -.148   .138                                                                               -.118                                                                              .000    -.102                                       8  .800    -.131   .122    -.103                                                                              -.090                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.42                                                                               3.01                                                                               -.56                                                                               2.71                                                                               -.85                                                                               2.16                                                                               -1.07                                                                              1.80                                        2  10.000                                                                             -.34                                                                               2.99                                                                               -.48                                                                               2.69                                                                               -.77                                                                               2.14                                                                               -1.00                                                                              1.79                                        3  5.000                                                                              -.26                                                                               2.98                                                                               -.40                                                                               2.67                                                                               -.69                                                                               2.13                                                                               -.92                                                                               1.78                                        4  3.000                                                                              -.14                                                                               2.90                                                                               -.29                                                                               2.62                                                                               -.59                                                                               2.11                                                                               -.81                                                                               1.77                                        5  2.000                                                                              .00 .00 -.15                                                                               2.59                                                                               -.45                                                                               2.08                                                                               -.67                                                                               1.75                                        6  1.500                                                                              .15 2.79                                                                               .00 .00 -.30                                                                               2.04                                                                               -.53                                                                               1.74                                        7  1.000                                                                              .46 2.73                                                                               .31 2.50                                                                               .00 .00 -.24                                                                               1.75                                        8  .800                                                                               .71 2.65                                                                               .55 2.43                                                                               .24 1.97                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.65, K.sub.aR      /γ.sub.aR = 1.59                                                   

                                      TABLE 34                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (70.0 mm) of Second Embodiment        F = 70.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.357                                                                              5.000                                                                              -.740                                                                              3.000                                                                              -1.295                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -1.419                                                                             .000    -1.347  -1.277  -1.189                                      2  10.000  -1.388                                                                             -1.317                                                                             .000    -1.248  -1.161                                      3  5.000   -1.354  -1.285                                                                             -1.217                                                                             .000    -1.133                                      4  3.000   -1.309  -1.241  -1.177                                                                             -1.096                                                                             .000                                        5  2.000   -1.254  -1.190  -1.129  -1.053                                      6  1.500   -1.197  -1.136  -1.078  -1.005                                      7  1.000   -1.064  -1.008  -.955   -.888                                       8  .800    -.947   .896    -.849   -.788                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.48                                                                               20.92                                                                              -.95                                                                               19.20                                                                              -1.54                                                                              18.17                                       2  10.000                                                                             .50 22.58                                                                              .00 .00 -.48                                                                               19.08                                                                              -1.09                                                                              18.29                                       3  5.000                                                                              1.00                                                                               22.11                                                                              .49 20.04                                                                              .00 .00 -.63                                                                               18.59                                       4  3.000                                                                              1.70                                                                               21.91                                                                              1.16                                                                               20.27                                                                              .65 19.45                                                                              .00 .00                                         5  2.000                                                                              2.59                                                                               22.31                                                                              2.03                                                                               21.04                                                                              1.50                                                                               20.52                                                                              .81 20.85                                       6  1.500                                                                              3.52                                                                               22.57                                                                              2.94                                                                               21.39                                                                              2.38                                                                               20.72                                                                              1.66                                                                               20.05                                       7  1.000                                                                              5.50                                                                               21.99                                                                              4.86                                                                               20.72                                                                              4.24                                                                               19.68                                                                              3.45                                                                               18.22                                       8  .800                                                                               7.10                                                                               21.34                                                                              6.40                                                                               20.06                                                                              5.74                                                                               18.93                                                                              4.89                                                                               17.38                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.068                                                                             1.500                                                                              -2.945                                                                             1.000                                                                              -5.176                                                                             .800                                                                               -7.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -1.087  -.992   -.808   -.675                                       2  10.000  -1.063  -.970   -.789   -.658                                       3  5.000   -1.038  -.948   -.770   -.642                                       4  3.000   -1.006  -.918   -.744   -.619                                       5  2.000                                                                              -.966                                                                              .000    -.879   -.709   -.588                                       6  1.500   -.919                                                                              -.834                                                                              .000    -.670   -.556                                       7  1.000   -.809   -.731                                                                              -.583                                                                              .000    -.484                                       8  .800    -.715   -.645   -.516                                                                              -.424                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -2.25                                                                              17.89                                                                              -2.92                                                                              15.43                                                                              -4.18                                                                              10.86                                                                              -5.06                                                                              8.59                                        2  10.000                                                                             -1.82                                                                              18.16                                                                              -2.51                                                                              15.44                                                                              -3.80                                                                              10.78                                                                              -4.70                                                                              8.54                                        3  5.000                                                                              -1.38                                                                              18.52                                                                              -2.09                                                                              15.40                                                                              -3.41                                                                              10.68                                                                              -4.34                                                                              8.48                                        4  3.000                                                                              -.78                                                                               18.86                                                                              -1.51                                                                              15.14                                                                              -2.89                                                                              10.49                                                                              -3.84                                                                              8.39                                        5  2.000                                                                              .00 .00 -.77                                                                               14.43                                                                              -2.20                                                                              10.24                                                                              -3.20                                                                              8.28                                        6  1.500                                                                              .81 16.70                                                                              .00 .00 -1.50                                                                              10.03                                                                              -2.53                                                                              8.19                                        7  1.000                                                                              2.51                                                                               15.43                                                                              1.63                                                                               13.16                                                                              .00 .00 -1.13                                                                              8.00                                        8  .800                                                                               3.88                                                                               14.96                                                                              2.94                                                                               12.98                                                                              1.20                                                                               10.34                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.67, K.sub.aR      /γ.sub.aR = 1.59                                                   

                                      TABLE 35                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (131.0 mm) of Second Embodiment         F = 131.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.356                                                                              5.000                                                                              -.744                                                                              3.000                                                                              -1.298                                      __________________________________________________________________________     POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -4.996                                                                             .000    -4.383  -3.869  -3.374                                      2  10.000  -4.934                                                                             -4.290                                                                             .000    -3.78l  -3.312                                      3  5.000   -4.829  -4.189                                                                             -3.722                                                                             .000    -3.275                                      4  3.000   -4.757  -4.140  -3.694                                                                             -3.222                                                                             .000                                        5  2.000   -4.660  -4.050  -3.597  -3.113                                      6  1.500   -4.544  -3.936  -3.482  -3.002                                      7  1.000   -4.248  -3.648  -3.201  -2.739                                      8  .800    -3.951  -3.365  -2.934  -2.494                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -1.56                                                                              72.38                                                                              -2.88                                                                              72.51                                                                              -4.38                                                                              93.08                                       2  10.000                                                                             1.75                                                                               139.72                                                                             .00 .00 -1.47                                                                              92.40                                                                              -3.12                                                                              112.40                                      3  5.000                                                                              3.59                                                                               107.18                                                                             1.63                                                                               68.79                                                                              .00 .00 -1.82                                                                              110.37                                      4  3.000                                                                              6.17                                                                               128.81                                                                             3.90                                                                               111.67                                                                             2.05                                                                               272.56                                                                             .00 .00                                         5  2.000                                                                              9.65                                                                               143.36                                                                             6.94                                                                               123.86                                                                             4.77                                                                               142.31                                                                             2.40                                                                               71.10                                       6  1.500                                                                              13.42                                                                              148.20                                                                             10.22                                                                              123.71                                                                             7.69                                                                               119.21                                                                             4.97                                                                               72.57                                       7  1.000                                                                              22.02                                                                              147.09                                                                             17.61                                                                              117.64                                                                             14.22                                                                              101.69                                                                             10.64                                                                              70.93                                       8  .800                                                                               29.63                                                                              141.55                                                                             24.04                                                                              111.52                                                                             19.82                                                                              93.70                                                                              15.47                                                                              68.41                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.070                                                                             1.500                                                                              -2.952                                                                             1.000                                                                              -5.184                                                                             .800                                                                               -7.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -2.885  -2.485  -1.854  -1.472                                      2  10.000  -2.833  -2.439  -1.817  -1.440                                      3  5.000   -2.793  -2.399  -1.781  -1.410                                      4  3.000   -2.729  -2.338  -1.729  -1.365                                      5  2.000                                                                              -2.631                                                                             .000    -2.252  -1.659  -1.306                                      6  1.500   -2.533                                                                             -2.163                                                                             .000    -1.583  -1.242                                      7  1.000   -2.294  -1.944                                                                             -1.405                                                                             .000    -1.098                                      8  .800    -2.076  -1.749  -1.258                                                                             -.966                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -5.97                                                                              61.81                                                                              -7.34                                                                              49.17                                                                              -9.61                                                                              30.11                                                                              -11.04                                                                             21.07                                       2  10.000                                                                             -4.86                                                                              63.05                                                                              -6.33                                                                              49.46                                                                              -8.77                                                                              29.96                                                                              -10.29                                                                             20.94                                       3  5.000                                                                              -3.70                                                                              59.96                                                                              -5.30                                                                              48.38                                                                              -7.91                                                                              29.57                                                                              -9.52                                                                              20.73                                       4  3.000                                                                              -2.11                                                                              56.51                                                                              -3.87                                                                              47.66                                                                              -6.72                                                                              29.14                                                                              -8.47                                                                              20.47                                       5  2.000                                                                              .00 .00 -1.99                                                                              47.94                                                                              -5.17                                                                              28.63                                                                              -7.09                                                                              20.14                                       6  1.500                                                                              2.24                                                                               59.82                                                                              .00 .00 -3.53                                                                              27.94                                                                              -5.65                                                                              19.75                                       7  1.000                                                                              7.14                                                                               55.80                                                                              4.34                                                                               42.89                                                                              .00 .00 -2.54                                                                              18.54                                       8  .800                                                                               11.27                                                                              53.40                                                                              7.96                                                                               41.63                                                                              2.91                                                                               27.69                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.79, K.sub.aR      /γ.sub.aR = 1.52                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the second embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.75 are as follows.

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            4.18           0.36                                                 (F = 28.8)                                                                     Middle Position                                                                           5.00           0.36                                                 (F = 70.0)                                                                     Telephoto End                                                                             6.51           0.35                                                 (F = 131.0)                                                                    Second Embodiment                                                              Wide-angle End                                                                            0.65           1.59                                                 (F = 28.8)                                                                     Middle Position                                                                           0.67           1.59                                                 (F = 70.0)                                                                     Telephoto End                                                                             0.79           1.52                                                 (F = 131.0)                                                                    ______________________________________                                    

As described above, in the third embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the second embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.75, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -8.1%         -21.4%                                               (F = 28.8)                                                                     Middle Position                                                                           -13.3%         -21.9%                                               (F = 70.0)                                                                     Telephoto End                                                                             -15.8%         -22.7%                                               (F = 131.0)                                                                    Second Embodiment                                                              Wide-angle End                                                                             -4.9%         -1.2%                                                (F = 28.8)                                                                     Middle Position                                                                           -2.1%          -0.7%                                                (F = 70.0)                                                                     Telephoto End                                                                             -0.3%          -1.0%                                                (F = 131.0)                                                                    ______________________________________                                    

As described above, in the second embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 36 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 28) of the second embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 36 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 70.0, 105.0, and 131.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 36                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Second Embodiment                             __________________________________________________________________________             0.80 m                                                                             1.00 m                                                                               1.50 m                                                                             2.00 m                                                                               3.00 m                                                                             5.00 m                                         __________________________________________________________________________     F 28.800 Bf                                                                            .000                                                                               .000  .000                                                                               .000  .000                                                                               ta .000                                        F 35.000 Bf                                                                            .000                                                                               .000  .002                                                                               .003  .003                                                                               .002                                           F 50.000 Bf                                                                            .000                                                                               .001  .001                                                                               -.002 -.004                                                                              -.003                                          F 70.000 Bf                                                                            .000                                                                               -.005 -.006                                                                              -.002 -.003                                                                              -.005                                          F 105.000 Bf                                                                           .000                                                                               -.011 -.020                                                                              -.017 -.018                                                                              -.016                                          F 131.000 Bf                                                                           .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           __________________________________________________________________________     ANGLE DA                                                                               -7.500                                                                             -5.184                                                                             -2.952                                                                              -2.070                                                                             -1.298 -.744                                          __________________________________________________________________________     F 28.800 DX                                                                            .000                                                                               .684                                                                               .000 .000                                                                               .000 R 0.80 m                                         F 35.000 DX                                                                            .000                                                                               .831                                                                               .000 .000                                                                               .000 R 0.80 m                                         F 50.000 DX                                                                            .000                                                                               1.222                                                                              .000 .000                                                                               .000 R 0.80 m                                         F 70.000 DX                                                                            .000                                                                               1.835                                                                              .000 .000                                                                               .000 R 0.80 m                                         F 105.000 DX                                                                           .000                                                                               3.204                                                                              .000 .000                                                                               .000 R 0.80 m                                         F 131.000 DX                                                                           .000                                                                               4.505                                                                              .000 .000                                                                               .000 r 0.80 m                                         F 28.800 DX                                                                            .000                                                                               .540                                                                               .000 .000                                                                               .000 R 1.00 m                                         F 35.000 DX                                                                            .000                                                                               .659                                                                               .000 .000                                                                               .000 R 1.00 m                                         F 50.000 DX                                                                            .000                                                                               .978                                                                               .000 .000                                                                               .000 R 1.00 m                                         F 70.000 DX                                                                            .000                                                                               1.492                                                                              .000 .000                                                                               .000 R 1.00 m                                         F 105.000 DX                                                                           .000                                                                               2.689                                                                              .000 .000                                                                               .000 R 1.00 m                                         F 131.000 DX                                                                           .000                                                                               3.879                                                                              .000 .000                                                                               .000 R 1.00 m                                         F 28.800 DX                                                                            .000                                                                               .354                                                                               .000 .000                                                                               .000 R 1.50 m                                         F 35.000 DX                                                                            .000                                                                               .433                                                                               .000 .000                                                                               .000 R 1.50 m                                         F 50.000 DX                                                                            .000                                                                               .653                                                                               .000 .000                                                                               .000 R 1.50 m                                         F 70.000 DX                                                                            .000                                                                               1.020                                                                              .000 .000                                                                               .000 R 1.50 m                                         F 105.000 DX                                                                           .000                                                                               1.934                                                                              .000 .000                                                                               .000 R 1.50 m                                         F 131.000 DX                                                                           .000                                                                               2.920                                                                              .000 .000                                                                               .000 R 1.50 m                                         F 28.800 DX                                                                            .000                                                                               .263                                                                               .000 .000                                                                               .000 R 2.00 m                                         F 35.000 DX                                                                            .000                                                                               .322                                                                               .000 .000                                                                               .000 R 2.00 m                                         F 50.000 DX                                                                            .000                                                                               .492                                                                               .000 .000                                                                               .000 R 2.00 m                                         F 70.000 DX                                                                            .000                                                                               .774                                                                               .000 .000                                                                               .000 R 2.00 m                                         F 105.000 DX                                                                           .000                                                                               1.515                                                                              .000 .000                                                                               .000 R 2.00 m                                         F 131.000 DX                                                                           .000                                                                               2.362                                                                              .000 .000                                                                               .000 R 2.00 m                                         F 28.800 DX                                                                            .000                                                                               .174                                                                               .000 .000                                                                               .000 R 3.00 m                                         F 35.000 DX                                                                            .000                                                                               .213                                                                               .000 .000                                                                               .000 R 3.00 m                                         F 50.000 DX                                                                            .000                                                                               .329                                                                               .000 .000                                                                               .000 R 3.00 m                                         F 70.000 DX                                                                            .000                                                                               .524                                                                               .000 .000                                                                               .000 R 3.00 m                                         F 105.000 DX                                                                           .000                                                                               1.063                                                                              .000 .000                                                                               .000 R 3.00 m                                         F 131.000 DX                                                                           .000                                                                               1.725                                                                              .000 .000                                                                               .000 R 3.00 m                                         F 28.800 DX                                                                            .000                                                                               .104                                                                               .000 .000                                                                               .000 R 5.00 m                                         F 35.000 DX                                                                            .000                                                                               .127                                                                               .000 .000                                                                               .000 R 5.00 m                                         F 50.000 DX                                                                            .000                                                                               .198                                                                               .000 .000                                                                               .000 R 5.00 m                                         F 70.000 DX                                                                            .000                                                                               .319                                                                               .000 .000                                                                               .000 R 5.00 m                                         F 105.000 DX                                                                           .000                                                                               .668                                                                               .000 .000                                                                               .000 R 5.00 m                                         F 131.000 DX                                                                           .000                                                                               1.131                                                                              .000 .000                                                                               .000 R 5.00 m                                         __________________________________________________________________________

As can be seen from Table 36, in the zoom lens of the second embodiment, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Third Embodiment!

The third embodiment is directed to a zoom lens which has a four-unit arrangement, i.e., positive, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.8 m) to the amount of rotation for zooming from the wide-angle end (F=36.0) to the telephoto end (F=131.0) is set to be -0.85.

Table 37 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the third embodiment.

The upper table in Table 37 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the third embodiment in association with six zooming states (focal length F=36.0 (1-POS), 50.0 (2-POS), 70.0 (3-POS), 85.0 (4-POS), 105.0 (5-POS), and 131.0 mm (6-POS)).

The middle table in Table 37 summarizes spline sample data when the shape of the focus cam in the second lens unit of the third embodiment, which is used for focusing, is expressed by a spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 37 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=36.0, 50.0, 70.0, 85.0, 105.0, and 131.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) using the focus cam of the third embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=36.0) to the telephoto end (F=131.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.8 m) is set to be -8.5, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the third embodiment is -0.85.

                                      TABLE 37                                     __________________________________________________________________________     Third Embodiment F = 36.0 to 131.0 (Rotation Amount Ratio:                     a.sub.F /a.sub.Z = -0.85)                                                      __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Third             Embodiment                                                                              1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                               6-POS                                          __________________________________________________________________________            F 36.0000                                                                            50.0000                                                                             70.0000                                                                            85.0000                                                                             105.0000                                                                            131.0000                                       F1                                                                               73.0000                                                                             D1                                                                               10.4075                                                                            17.8050                                                                             24.9191                                                                            28.6662                                                                             32.4300                                                                             36.0004                                        F2                                                                               -16.6000                                                                            D2                                                                               25.6151                                                                            21.3295                                                                             17.3824                                                                            15.1421                                                                             12.6290                                                                             9.7969                                         F3                                                                               42.0000                                                                             D3                                                                               10.0000                                                                            9.2923                                                                              8.2560                                                                             7.6919                                                                              7.2951                                                                              7.2634                                         F4                                                                               80.0000                                                                             D4                                                                               63.8473                                                                            70.6899                                                                             77.4519                                                                            81.1930                                                                             85.0439                                                                             88.8003                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding              to Third Embodiment                                                               ANGLE     (1)                                                                               (2)       (3)                                                                               (4)                                               __________________________________________________________________________     1  -10.0000  .0000                                                                             1.1480    .0000                                                                             .0000                                             2  -8.5000   .0000                                                                             1.0414    .0000                                                                             .0000                                             3  -5.9359   .0000                                                                             .8252     .0000                                                                             .0000                                             4  -3.4109   .0000                                                                             .5436     .0000                                                                             .0000                                             5  -2.3987   .0000                                                                             .4054     .0000                                                                             .0000                                             6  -1.5068   .0000                                                                             .2688     .0000                                                                             .0000                                             7  -.8645    .0000                                                                             .1606     .0000                                                                             .0000                                             8  .0000     .0000                                                                             .0000     .0000                                                                             .0000                                             9  1.5000    .0000                                                                             -.3253    .0000                                                                             .0000                                             10 4.0641    .0000                                                                             -1.0736   .0000                                                                             .0000                                             11 6.5891    .0000                                                                             -2.2211   .0000                                                                             .0000                                             12 7.6013    .0000                                                                             -2.8951   .0000                                                                             .0000                                             13 8.4932    .0000                                                                             -3.6785   .0000                                                                             .0000                                             14 9.1355    .0000                                                                             -4.4302   .0000                                                                             .0000                                             15 10.0000   .0000                                                                             -6.0011   .0000                                                                             .0000                                             16 11.0000   .0000                                                                             -9.5000   .0000                                                                             .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Third Embodiment                                                               Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.85)                               __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal Length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     36.0 mm        .0000  5.00 m    .865                                           50.0 mm        2.9527                                                                                3.00 m    -1.507                                         70.0 mm        5.9439                                                                                2.00 m    -2.399                                         85.0 mm        7.4823                                                                                1.50 m    -3.411                                         105.0 mm       8.9096                                                                                1.00 m    -5.936                                         131.0 mm       10.0000                                                                               0.80 m    -8.500                                         Condition Corresponding Value (1)                                                                    2.30                                                     Condition Corresponding Value (2)                                                                    5.45                                                     Condition Corresponding Value (3)                                                                   -0.85                                                     Condition Corresponding Value (4)                                                                    0.40 (wide-angle end)                                                          0.21 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.68 (wide-angle end)                                                          0.80 (telephoto end)                                     Condition Corresponding Value (6)                                                                    1.52 (wide-angle end)                                                          1.43 (telephoto end)                                     __________________________________________________________________________

Table 38 below summarizes the numerical value data of the cams of the focusing lens unit in the third embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 37. Note that the meanings of the reference symbols in Table 38 are the same as those in the first embodiment.

                  TABLE 38                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Third                        Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)       F        ANGLE  (2)    F                                      ______________________________________                                         -8.5000                                                                               1.0414    .0000                                                         -8.0000                                                                               1.0035    .0000                                                         -7.5000                                                                               .9637     .0000                                                         -7.0000                                                                               .9219     .0000                                                         -6.5000                                                                               .8779     .0000                                                         -6.0000                                                                               .8314     .0000                                                         -5.5000                                                                               .7823     .0000                                                         -5.0000                                                                               .7303     .0000                                                         -4.5000                                                                               .6752     .0000                                                         -4.0000                                                                               .6168     .0000                                                         -3.5000                                                                               .5550     .0000                                                         -3.0000                                                                               .4895     .0000                                                         -2.5000                                                                               .4200     .0000                                                         -2.0000                                                                               .3462     .0000                                                         -1.5000                                                                               .2677     .0000                                                         -1.0000                                                                               .1842     .0000                                                         -.5000 .0951     .0000                                                         .0000  .0000     36.0000  .0000  .0000  36.0000                                .5000  -.1013    38.1000  .5000  .4231  38.1000                                1.0000 -.2095    40.2980  1.0000 .8495  40.2980                                1.5000 -.3253    42.6028  1.5000 1.2799 42.6028                                2.0000 -.4495    45.0229  2.0000 1.7151 45.0229                                2.5000 -.5832    47.5713  2.5000 2.1565 47.5713                                3.0000 -.7273    50.2608  3.0000 2.6053 50.2608                                3.5000 -.8829    53.1017  3.5000 3.0625 53.1017                                4.0000 -1.0511   56.1044  4.0000 3.5285 56.1044                                4.5000 -1.2331   59.2847  4.5000 4.0048 59.2847                                5.0000 -1.4322   62.6993  5.0000 4.4979 62.6993                                5.5000 -1.6521   66.4118  5.5000 5.0141 66.4118                                6.0000 -1.8965   70.4744  6.0000 5.5582 70.4744                                6.5000 -2.1693   74.9275  6.5000 6.1332 74.9275                                7.0000 -2.4745   79.8072  7.0000 6.7425 79.8072                                7.5000 -2.8196   85.2003  7.5000 7.3952 85.2003                                8.0000 -3.2152   91.2332  8.0000 8.1044 91.2332                                8.5000 -3.6854   98.2632  8.5000 8.9050 98.2632                                9.0000 -4.2566   106.6077 9.0000 9.8265 106.6077                               9.5000 -4.9586   116.5539 9.5000 10.8970                                                                               116.5539                               10.0000                                                                               -6.0011   131.0000 10.0000                                                                               12.3994                                                                               131.0000                               ______________________________________                                    

The left table in Table 38 summarizes the numerical value data of the focus cam of the third embodiment, and the right table in Table 38 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 37.

Tables 39, 40, and 41 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=36.0), the middle position (F=70.0), and the telephoto end (F=131.0) according to the third embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 39                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End (36.0 mm) in Third Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.419                                                                              1)                                                                               .000                                                                               2)                                                                               .080                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               .161                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               .269                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               .405                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               .544                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               .825                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.041                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Wide-angle End (36.0       mm) in Third                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.361                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 10.000                                                                             ANG                                                                               -.419                                                                              1)                                                                               -.007                                                                              2)                                                                               -.356                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               -.015                                                                              2)                                                                               -.351                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               -.026                                                                              2)                                                                               -.345                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               -.040                                                                              2)                                                                               -.337                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               -.055                                                                              2)                                                                               -.328                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               -.089                                                                              2)                                                                               -.311                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               -.118                                                                              2)                                                                               -.298                                                                              3)                                                                               -6.767                                                                             4)                                                                               .202                                          Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at                                                                        Wide-angle End (36.0 mm) in Third Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.624                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.419                                                                              1)                                                                               .000                                                                               2)                                                                               1.630                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               1.637                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               1.645                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               1.655                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               1.666                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               1.686                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               1.701                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cain at Wide-angle End (36.0 mm) in Third                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.196                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.419                                                                              1)                                                                               .000                                                                               2)                                                                               -.186                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               -.176                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               -.162                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               -.145                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.129                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               -.096                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.074                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle                                                         End (36.0 mm) in Third Embodiment                                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.319                                                                              3)                                                                               .090                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.419                                                                              1)                                                                               .000                                                                               2)                                                                               -.303                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               -.287                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               -.266                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               -.240                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.214                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               -.162                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.126                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.05,         γ.sub.aR /γ.sub.a0 = 0.40                                    

                                      TABLE 40                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle Position (70.0 mm) in Third Embodiment                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.416                                                                              1)                                                                               .000                                                                               2)                                                                               .203                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.862                                                                              1)                                                                               .000                                                                               2)                                                                               .401                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.508                                                                             1)                                                                               .000                                                                               2)                                                                               .659                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.406                                                                             1)                                                                               .000                                                                               2)                                                                               .972                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.419                                                                             1)                                                                               .000                                                                               2)                                                                               1.278                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.942                                                                             1)                                                                               .000                                                                               2)                                                                               1.867                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               2.296                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Middle Position (70.0      mm) in Third                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.527                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 10.000                                                                             ANG                                                                               -.416                                                                              1)                                                                               -.007                                                                              2)                                                                               -.515                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 5.000                                                                              ANG                                                                               -.862                                                                              1)                                                                               -.015                                                                              2)                                                                               -.503                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 3.000                                                                              ANG                                                                               -1.508                                                                             1)                                                                               -.026                                                                              2)                                                                               -.488                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 2.000                                                                              ANG                                                                               -2.406                                                                             1)                                                                               -.041                                                                              2)                                                                               -.469                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 1.500                                                                              ANG                                                                               -3.419                                                                             1)                                                                               -.056                                                                              2)                                                                               -.450                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R 1.000                                                                              ANG                                                                               -5.942                                                                             1)                                                                               -.091                                                                              2)                                                                               -.415                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               -.122                                                                              2)                                                                               -.389                                                                              3)                                                                               -57.094                                                                            4)                                                                               .032                                          Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle                                                                 Position (70.0 mm) in Third Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               2.387                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.416                                                                              1)                                                                               .000                                                                               2)                                                                               2.430                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.862                                                                              1)                                                                               .000                                                                               2)                                                                               2.470                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.508                                                                             1)                                                                               .000                                                                               2)                                                                               2.521                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.406                                                                             1)                                                                               .000                                                                               2)                                                                               2.580                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.419                                                                             1)                                                                               .000                                                                               2)                                                                               2.636                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.942                                                                             1)                                                                               .000                                                                               2)                                                                               2.738                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               2.807                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Middle Position (70.0 mm) in Third                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.510                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.416                                                                              1)                                                                               .000                                                                               2)                                                                               -.466                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.862                                                                              1)                                                                               .000                                                                               2)                                                                               -.425                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.508                                                                             1)                                                                               .000                                                                               2)                                                                               -.376                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.406                                                                             1)                                                                               .000                                                                               2)                                                                               -.325                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.419                                                                             1)                                                                               .000                                                                               2)                                                                               -.278                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.942                                                                             1)                                                                               .000                                                                               2)                                                                               -.196                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.142                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle                                                             Position (70.0 mm) in Third Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -1.217                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.416                                                                              1)                                                                               .000                                                                               2)                                                                               -1.132                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.862                                                                              1)                                                                               .000                                                                               2)                                                                               -1.049                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.508                                                                             1)                                                                               .000                                                                               2)                                                                               -.947                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.406                                                                             1)                                                                               .000                                                                               2)                                                                               -.840                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.419                                                                             1)                                                                               .000                                                                               2)                                                                               -.734                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.942                                                                             1)                                                                               .000                                                                               2)                                                                               -.537                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.399                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.18,         γ.sub.aR /γ.sub.a0 = 0.33                                    

                                      TABLE 41                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End (131.0 mm) in Third Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.407                                                                              1)                                                                               .000                                                                               2)                                                                               .884                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               1.571                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               2.323                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               3.106                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               3.780                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               4.928                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               5.676                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Telephoto End (131.0       mm) in Third                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.814                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 10.000                                                                             ANG                                                                               -.407                                                                              1)                                                                               -.007                                                                              2)                                                                               -.760                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               -.015                                                                              2)                                                                               -.719                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               -.026                                                                              2)                                                                               -.674                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               -.041                                                                              2)                                                                               -.627                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               -.057                                                                              2)                                                                               -.586                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               -.093                                                                              2)                                                                               -.517                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               -.125                                                                              2)                                                                               -.472                                                                              3)                                                                               20.047                                                                             4)                                                                               -.110                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at                                                                        Telephoto End (131.0 mm) in Third Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.643                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.407                                                                              1)                                                                               .000                                                                               2)                                                                               2.051                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               2.348                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               2.655                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               2.954                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               3.193                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               3.564                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               3.781                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Telephoto End (131.0 mm) in Third Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -2.632                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.407                                                                              1)                                                                               .000                                                                               2)                                                                               -1.779                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               -1.312                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               -1.033                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               -.756                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.588                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               -.353                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.240                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto                                                          End (131.0 nnn) in Third Embodiment                                            R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -4.324                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.407                                                                              1)                                                                               .000                                                                               2)                                                                               -3.647                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.865                                                                              1)                                                                               .000                                                                               2)                                                                               -3.081                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.507                                                                             1)                                                                               .000                                                                               2)                                                                               -2.742                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.399                                                                             1)                                                                               .000                                                                               2)                                                                               -2.233                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.411                                                                             1)                                                                               .000                                                                               2)                                                                               -1.877                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -5.936                                                                             1)                                                                               .000                                                                               2)                                                                               -1.258                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R .800                                                                               ANG                                                                               -8.500                                                                             1)                                                                               .000                                                                               2)                                                                               -.906                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 2.30,         γ.sub.aR /γ.sub.a0 = 0.21                                    

As can be seen from Tables 39, 40, and 41, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475. From Tables 39, 40, and 41, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.40 at the wide-angle end (F=36.0), ×0.33 at the middle position (F=70.0), and ×0.21 at the telephoto end (F=131.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the fourth embodiment is calculated using formula (a), and is compared with that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

When the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0

    N.sub.W >12.4 N.sub.M >12.6 N.sub.T >10.8

Third Embodiment

    N.sub.W >5.1 N.sub.M >6.1 N.sub.T >8.6

Therefore, it can be seen that the numbers of divisions become small, compared to those in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

As described above, in the third embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is smaller than that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, like in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 42, 43, and 44 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=36.0), middle position (F=70.0), and telephoto end (F=131.0) according to the third embodiment. The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 42, 43, and 44, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 42, 43, and 44, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.8, -8.5), and it indicates that this position corresponds to the closest in-focus (R=0.8 m) corresponding position.

                                      TABLE 42                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (36.0 mm) of Third Embodiment          F = 36.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.419                                                                              5.000                                                                              -.865                                                                              3.000                                                                              -1.507                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.319                                                                              .000    -.309   -.300   -.287                                       2  10.000  -.312                                                                              -.303                                                                              .000    -.294   -.281                                       3  5.000   -.306   -.297                                                                              -.287                                                                              .000    -.275                                       4  3.000   -.296   -.287   -.278                                                                              -.266                                                                              .000                                        5  2.000   -.284   -.275   -.267   -.255                                       6  1.500   -.271   -.263   -.254   -.243                                       7  1.000   -.242   -.235   -.227   -.217                                       8  .800    -.217   -.210   -.203   -.194                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.13                                                                               6.41                                                                               -.26                                                                               5.91                                                                               -.43                                                                               5.51                                        2  10.000                                                                             .13 6.83                                                                               .00 .00 -.13                                                                               5.75                                                                               -.31                                                                               5.45                                        3  5.000                                                                              .26 6.65                                                                               .13 6.16                                                                               .00 .00 -.18                                                                               5.44                                        4  3.000                                                                              .45 6.45                                                                               .31 6.01                                                                               .18 5.69                                                                               .00 .00                                         5  2.000                                                                              .68 6.32                                                                               .55 5.95                                                                               .41 5.69                                                                               .23 5.42                                        6  1.500                                                                              .92 6.22                                                                               .79 5.89                                                                               .65 5.64                                                                               .46 5.34                                        7  1.000                                                                              1.44                                                                               6.00                                                                               1.29                                                                               5.71                                                                               1.15                                                                               5.47                                                                               .96 5.16                                        8  .800                                                                               1.85                                                                               5.82                                                                               1.70                                                                               5.55                                                                               1.55                                                                               5.31                                                                               1.36                                                                               5.00                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.399                                                                             1.500                                                                              -3.411                                                                             1.000                                                                              -5.936                                                                             800 -8.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.270   -.254   -.219   -.192                                       2  10.000  -.265   -.248   -.214   -.187                                       3  5.000   -.259   -.243   -.209   -.183                                       4  3.000   -.251   -.235   -.202   -.177                                       5  2.000                                                                              -.240                                                                              .000    -.225   -.193   -.169                                       6  1.500   -.229                                                                              -.214                                                                              .000    -.184   -.160                                       7  1.000   -.203   -.190                                                                              -.162                                                                              .000    -.141                                       8  .800    -.182   -.170   -.145                                                                              -.126                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.65                                                                               5.11                                                                               -.87                                                                               4.69                                                                               -1.30                                                                              3.72                                                                               -1.63                                                                              3.16                                        2  10.000                                                                             -.52                                                                               5.07                                                                               -.74                                                                               4.67                                                                               -1.18                                                                              3.69                                                                               -1.51                                                                              3.14                                        3  5.000                                                                              -.40                                                                               5.05                                                                               -.62                                                                               4.65                                                                               -4.06                                                                              3.67                                                                               -1.40                                                                              3.13                                        4  3.000                                                                              -.22                                                                               5.01                                                                               -.45                                                                               4.61                                                                               -.90                                                                               3.63                                                                               -1.24                                                                              3.11                                        5  2.000                                                                              .00 .00 -.23                                                                               4.58                                                                               -.68                                                                               3.57                                                                               -1.03                                                                              3.09                                        6  1.500                                                                              .23 4.92                                                                               .00 .00 -.46                                                                               3.51                                                                               -.51                                                                               3.07                                        7  1.000                                                                              .72 4.73                                                                               .48 4.27                                                                               .00 .00 -.36                                                                               3.14                                        8  .800                                                                               1.11                                                                               4.59                                                                               .86 4.16                                                                               .37 3.41                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.68, K.sub.aR      /γ.sub.aR = 1.52                                                   

                                      TABLE 43                                     __________________________________________________________________________     Converison Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (70.0 mm) of Third Embodiment         F = 70.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.416                                                                              5.000                                                                              -.862                                                                              3.000                                                                              -1.508                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -1.217                                                                             .000    -1.156  -1.097  -1.021                                      2  10.000  -1.192                                                                             -1.131                                                                             .000    -1.073  -.999                                       3  5.000   -1.166  -1.106                                                                             -1.049                                                                             .000    -.977                                       4  3.000   -1.129  -1.071  -1.016                                                                             -.947                                                                              .000                                        5  2.000   -1.085  -1.030  -.978   -.913                                       6  1.500   -1.041  -.988   -.938   -.877                                       7  1.000   -.940   -.892   -.847   -.790                                       8  .800    -.851   -.807   -.766   -.713                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.48                                                                               22.24                                                                              -.95                                                                               20.78                                                                              -1.54                                                                              19.68                                       2  10.000                                                                             .50 24.26                                                                              .00 .00 -.48                                                                               20.47                                                                              -1.09                                                                              19.78                                       3  5.000                                                                              1.00                                                                               23.94                                                                              .49 22.26                                                                              .00 .00 -.63                                                                               20.21                                       4  3.000                                                                              1.70                                                                               23.67                                                                              1.17                                                                               22.08                                                                              .66 20.89                                                                              .00 .00                                         5  2.000                                                                              2.61                                                                               24.13                                                                              2.05                                                                               22.88                                                                              1.51                                                                               22.21                                                                              .82 22.79                                       6  1.500                                                                              3.56                                                                               24.62                                                                              2.97                                                                               23.47                                                                              2.40                                                                               22.79                                                                              1.67                                                                               22.47                                       7  1.000                                                                              5.59                                                                               24.59                                                                              4.93                                                                               23.35                                                                              4.30                                                                               22.35                                                                              3.50                                                                               21.08                                       8  .800                                                                               7.24                                                                               24.10                                                                              6.53                                                                               22.81                                                                              5.85                                                                               21.66                                                                              4.98                                                                               20.16                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.406                                                                             1.500                                                                              -3.419                                                                             1.000                                                                              -5.942                                                                             .800                                                                               -8.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.935   -.856   -.707   -.599                                       2  10.000  -.916   -.839   -.692   -.586                                       3  5.000   -.896   -.821   -.677   -.573                                       4  3.000   -.870   -.798   -.657   -.555                                       5  2.000                                                                              -.840                                                                              .000    -.768   -.630   -.532                                       6  1.500   -.804                                                                              -.734                                                                              .000    -.601   -.506                                       7  1.000   -.722   -.658                                                                              -.537                                                                              .000    -.450                                       8  .800    -.651   -.591   -.480                                                                              -.399                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -2.25                                                                              19.72                                                                              -2.93                                                                              17.58                                                                              -4.20                                                                              13.32                                                                              -5.09                                                                              10.17                                       2  10.000                                                                             -1.82                                                                              20.08                                                                              -2.52                                                                              17.68                                                                              -3.82                                                                              13.29                                                                              -4.74                                                                              10.11                                       3  5.000                                                                              -1.38                                                                              20.62                                                                              -2.10                                                                              17.76                                                                              -3.44                                                                              13.23                                                                              -4.38                                                                              10.04                                       4  3.000                                                                              -.78                                                                               21.31                                                                              -1.52                                                                              17.62                                                                              -2.91                                                                              13.10                                                                              -3.88                                                                              9.92                                        5  2.000                                                                              .00 .00 -.78                                                                               16.93                                                                              -2.23                                                                              12.88                                                                              -3.24                                                                              9.75                                        6  1.500                                                                              .81 19.42                                                                              .00 .00 -1.52                                                                              12.75                                                                              -2.57                                                                              9.57                                        7  1.000                                                                              2.55                                                                               18.30                                                                              1.66                                                                               15.95                                                                              .00 .00 -1.15                                                                              9.08                                        8  .800                                                                               3.97                                                                               17.62                                                                              3.00                                                                               15.44                                                                              1.23                                                                               11.49                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.70, K.sub.aR      /γ.sub.aR = 1.50                                                   

                                      TABLE 44                                     __________________________________________________________________________     Converison Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (131.0 mm) of Third Embodiment          F = 131.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.407                                                                              5.000                                                                              -.865                                                                              3.000                                                                              -1.507                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -4.321                                                                             .000    -3.765  -3.255  -2.839                                      2  10.000  -4.308                                                                             -3.649                                                                             .000    -3.138  -2.773                                      3  5.000   -4.152  -3.496                                                                             -3.080                                                                             .000    -2.764                                      4  3.000   -4.096  -3.491  -3.121                                                                             -2.741                                                                             .000                                        5  2.000   4.018   -3.428  -3.043  -2.635                                      6  1.500   -3.929  -3.346  -2.956  -2.553                                      7  1.000   -3.703  -3.132  -2.745  -2.356                                      8  .800    -3.477  -2.919  -2.544  -2.171                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -1.53                                                                              48.23                                                                              -2.81                                                                              49.46                                                                              -4.28                                                                              119.60                                      2  10.000                                                                             1.75                                                                               572.58                                                                             .00 .00 -1.43                                                                              77.03                                                                              3.05                                                                               257.36                                      3  5.000                                                                              3.59                                                                               91.70                                                                              1.60                                                                               38.08                                                                              .00 .00 -1.77                                                                              212.10                                      4  3.000                                                                              6.17                                                                               118.29                                                                             3.84                                                                               88.33                                                                              2.00                                                                               -152.43                                                                            .00 .00                                         5  2.000                                                                              9.64                                                                               137.16                                                                             6.83                                                                               112.61                                                                             4.67                                                                               386.10                                                                             2.35                                                                               61.08                                       6  1.500                                                                              13.40                                                                              147.45                                                                             10.05                                                                              120.80                                                                             7.53                                                                               187.07                                                                             4.86                                                                               71.08                                       7  1.000                                                                              21.98                                                                              153.73                                                                             17.31                                                                              122.07                                                                             13.92                                                                              128.09                                                                             10.44                                                                              74.42                                       8  .800                                                                               29.56                                                                              151.27                                                                             23.63                                                                              118.12                                                                             19.42                                                                              111.54                                                                             15.19                                                                              73.11                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.399                                                                             1.500                                                                              -3.411                                                                             1.000                                                                              -5.936                                                                             .800                                                                               -8.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -2.436  -2.113  -1.606  -1.298                                      2  10.000  -2.388  -2.073  -1.576  -1.273                                      3  5.000   -2.366  -2.048  -1.551  -1.250                                      4  3.000   -2.315  -2.001  -1.511  -1.216                                      5  2.000                                                                              -2.232                                                                             .000    -1.938  -1.458  -1.170                                      6  1.500   -2.171                                                                             -1.877                                                                             .000    -1.400  -1.120                                      7  1.000   -1.991  -1.704                                                                             -1.258                                                                             .000    -1.007                                      8  .800    -1.825  -1.555  -1.146                                                                             -.906                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -5.84                                                                              63.88                                                                              -7.21                                                                              57.34                                                                              -9.53                                                                              34.47                                                                              -11.03                                                                             25.55                                       2  10.000                                                                             -4.76                                                                              67.97                                                                              -6.23                                                                              59.58                                                                              -8.71                                                                              34.51                                                                              -10.30                                                                             25.49                                       3  5.000                                                                              -3.63                                                                              60.51                                                                              -5.21                                                                              57.33                                                                              -7.86                                                                              33.81                                                                              -9.54                                                                              25.18                                       4  3.000                                                                              -2.06                                                                              55.43                                                                              -3.81                                                                              57.76                                                                              -6.69                                                                              33.28                                                                              -8.50                                                                              24.92                                       5  2.000                                                                              .00 .00 -1.96                                                                              60.83                                                                              -5.16                                                                              32.47                                                                              -7.14                                                                              24.56                                       6  1.500                                                                              2.20                                                                               80.09                                                                              .00 .00 -3.53                                                                              31.39                                                                              -5.70                                                                              24.18                                       7  1.000                                                                              7.04                                                                               65.19                                                                              4.30                                                                               46.70                                                                              .00 .00 -2.58                                                                              23.32                                       8  .800                                                                               11.13                                                                              61.04                                                                              7.91                                                                               46.13                                                                              2.94                                                                               33.11                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.80, K.sub.aR      /γ.sub.aR = 1.43                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the third embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.85 are as follows.

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            3.94           0.36                                                 (F = 28.8)                                                                     Middle Position                                                                           5.21           0.37                                                 (F = 70.0)                                                                     Telephoto End                                                                             6.78           0.35                                                 (F = 131.0)                                                                    Third Embodiment                                                               Wide-angle End                                                                            0.68           1.52                                                 (F = 28.8)                                                                     Middle Position                                                                           0.70           1.50                                                 (F = 70.0)                                                                     Telephoto End                                                                             0.80           1.43                                                 (F = 131.0)                                                                    ______________________________________                                    

As described above, in the third embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the third embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.85, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -8.5%         -20.9%                                               (F = 36.0)                                                                     Middle Position                                                                           -14.1%         -23.8%                                               (F = 70.0)                                                                     Telephoto End                                                                             -17.8%         -23.3%                                               (F = 131.0)                                                                    Third Embodiment                                                               Wide-angle End                                                                             -3.5%         -0.1%                                                (F = 36.0)                                                                     Middle Position                                                                           -0.0%          -0.8%                                                (F = 70.0)                                                                     Telephoto End                                                                             2.6%           -0.7%                                                (F = 131.0)                                                                    ______________________________________                                    

As described above, in the third embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 45 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 37) of the third embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 45 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) in the respective zooming states of the focal lengths (F=36.0, 50.0, 70.0, 85.0, 105.0, and 131.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                  TABLE 45                                                         ______________________________________                                         Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Third Embodiment                              ______________________________________                                                  0.80 m  1.00 m  1.50 m                                                                               2.00 m                                                                               3.00 m                                                                               5.00 m                              ______________________________________                                         36.000 Bf                                                                               .000    .000    .000  .000  .000  .000                                50.000 Bf                                                                               .000    -.001   .000  .001  .001  .001                                70.000 Bf                                                                               .000    .003    .006  .006  .001  -.003                               85.000 Bf                                                                               .000    .002    -.001 -.011 -.010 -.004                               105.000 Bf                                                                              .000    -.001   -.018 -.012 -.012 -.019                               131.000 Bf                                                                              .000    .000    .000  .000  .000  .000                                ______________________________________                                             ANGLE DA  -8.500  -5.936                                                                               -3.411                                                                               -2.399                                                                               -1.507                                                                               -.865                            ______________________________________                                         F   36.000 DX .000    1.041 .000  .000 R                                                                               0.80 m                                 F   50.000 DX .000    1.500 .000  .000 R                                                                               0.80 m                                 F   70.000 DX .000    2.296 .000  .000 R                                                                               0.80 m                                 F   85.000 DX .000    2.994 .000  .000 R                                                                               0.80 m                                 F   105.000 DX                                                                               .000    4.063 .000  .000 R                                                                               0.80 m                                 F   131.000 DX                                                                               .000    5.676 .000  .000 R                                                                               0.80 m                                 F   36.000 DX .000    .825  .000  .000 R                                                                               1.00 m                                 F   50.000 DX .000    1.200 .000  .000 R                                                                               1.00 m                                 F   70.000 DX .000    1.866 .000  .000 R                                                                               1.00 m                                 F   85.000 DX .000    2.470 .000  .000 R                                                                               1.00 m                                 F   105.000 DX                                                                               .000    3.426 .000  .000 R                                                                               1.00 m                                 F   131.000 DX                                                                               .000    4.928 .000  .000 R                                                                               1.00 m                                 F   36.000 DX .000    .544  .000  .000 R                                                                               1.50 m                                 F   50.000 DX .000    .801  .000  .000 R                                                                               1.50 m                                 F   70.000 DX .000    1.275 .000  .000 R                                                                               1.50 m                                 F   85.000 DX .000    1.730 .000  .000 R                                                                               1.50 m                                 F   105.000 DX                                                                               .000    2.494 .000  .000 R                                                                               1.50 m                                 F   131.000 DX                                                                               .000    3.780 .000  .000 R                                                                               1.50 m                                 F   36.000 DX .000    .405  .000  .000 R                                                                               2.00 m                                 F   50.000 DX .000    .601  .000  .000 R                                                                               2.00 m                                 F   70.000 DX .000    .970  .000  .000 R                                                                               2.00 m                                 F   85.000 DX .000    1.339 .000  .000 R                                                                               2.00 m                                 F   105.000 DX                                                                               .000    1.970 .000  .000 R                                                                               2.00 m                                 F   131.000 DX                                                                               .000    3.106 .000  .000 R                                                                               2.00 m                                 F   36.000 DX .000    .269  .000  .000 R                                                                               3.00 m                                 F   50.000 DX .000    .401  .000  .000 R                                                                               3.00 m                                 F   70.000 DX .000    .658  .000  .000 R                                                                               3.00 m                                 F   85.000 DX .000    .923  .000  .000 R                                                                               3.00 m                                 F   105.000 DX                                                                               .000    1.396 .000  .000 R                                                                               3.00 m                                 F   131.000 DX                                                                               .000    2.323 .000  .000 R                                                                               3.00 m                                 F   36.000 DX .000    .161  .000  .000 R                                                                               5.00 m                                 F   50.000 DX .000    .241  .000  .000 R                                                                               5.00 m                                 F   70.000 DX .000    .402  .000  .000 R                                                                               5.00 m                                 F   85.000 DX .000    .569  .000  .000 R                                                                               5.00 m                                 F   105.000 DX                                                                               .000    .891  .000  .000 R                                                                               5.00 m                                 F   131.000 DX                                                                               .000    1.571 .000  .000 R                                                                               5.00 m                                 ______________________________________                                    

As can be seen from Table 45, in the zoom lens of the third embodiment, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Fourth Embodiment!

The fourth embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, positive, negative and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.5 m) to the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=103.0) is set to be -0.90.

Table 46 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the fourth embodiment.

The upper table in Table 46 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the fourth embodiment in association with six zooming states (focal length F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 70.0 (4-POS), 85.0 (5-POS), and 103.0 mm (6-POS)).

The middle table in Table 46 summarizes spline sample data when the shape of the focus cam in the second lens unit of the fourth embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 46 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (focal length F=28.8, 35.0, 50.0, 70.0, 85.0, and 103.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.0, 0.7, and 0.5 m) using the focus cam of the fourth embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=103.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.5 m) is set to be -9.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the fourth embodiment is -0.90.

                                      TABLE 46                                     __________________________________________________________________________     Fourth Embodiment F = 28.8 to 103.0 (Rotation Amount Ratio: a.sub.F            /a.sub.Z = -0.90)                                                              Focal lengths and Principal Point Intervals of Lens Units of Fourth            Embodiment                                                                               1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                              6-POS                                          __________________________________________________________________________            F  28.8000                                                                            35.0000                                                                             50.0000                                                                            70.0000                                                                             85.0000                                                                            103.0000                                       F1                                                                               70.5000                                                                             D1 9.3252                                                                             13.0113                                                                             20.5346                                                                            28.4581                                                                             32.6851                                                                            36.5544                                        F2                                                                               -13.4000                                                                            D2 18.3082                                                                            16.1329                                                                             13.0216                                                                            10.6580                                                                             9.2279                                                                             7.6539                                         F3                                                                               32.9000                                                                             D3 14.6453                                                                            13.3678                                                                             10.4573                                                                            8.4188                                                                              7.8210                                                                             7.5173                                         F4                                                                               56.4000                                                                             D4 49.9916                                                                            54.4242                                                                             61.6013                                                                            65.7605                                                                             67.3873                                                                            68.3296                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding              to Fourth Embodiment                                                              ANGLE     (1)                                                                               (2)       (3)                                                                               (4)                                               __________________________________________________________________________     1  -10.0000  .0000                                                                             .9890     .0000                                                                             .0000                                             2  -9.0000   .0000                                                                             .9281     .0000                                                                             .0000                                             3  -5.2174   .0000                                                                             .6450     .0000                                                                             .0000                                             4  -3.2226   .0000                                                                             .4427     .0000                                                                             .0000                                             5  -1.4215   .0000                                                                             .2166     .0000                                                                             .0000                                             6  -.9122    .0000                                                                             .1434     .0000                                                                             .0000                                             7  -.5316    .0000                                                                             .0856     .0000                                                                             .0000                                             8  .0000     .0000                                                                             .0000     .0000                                                                             .0000                                             9  1.0000    .0000                                                                             -.1755    .0000                                                                             .0000                                             10 4.7826    .0000                                                                             -1.1178   .0000                                                                             .0000                                             11 6.7774    .0000                                                                             -1.9212   .0000                                                                             .0000                                             12 8.5785    .0000                                                                             -3.0359   .0000                                                                             .0000                                             13 9.0878    .0000                                                                             -3.4750   .0000                                                                             .0000                                             14 9.4684    .0000                                                                             -3.8631   .0000                                                                             .0000                                             15 10.0000   .0000                                                                             -4.5317   .0000                                                                             .0000                                             16 11.0000   .0000                                                                             -6.2650   .0000                                                                             .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Fourth Embodiment                                                              Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.90)                               __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal Length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     28.8 mm        .0000  5.00 m    -.532                                          35.0 mm        1.3907                                                                                3.00 m    -.912                                          50.0 mm        4.2613                                                                                2.00 m    -1.421                                         70.0 mm        7.2647                                                                                1.00 m    -3.223                                         85.0 mm        8.7737                                                                                0.70 m    -5.217                                         103.0 mm       10.0000                                                                               0.50 m    -9.000                                         Condition Corresponding Value (1)                                                                    1.55                                                     Condition Corresponding Value (2)                                                                    4.69                                                     Condition Corresponding Value (3)                                                                   -0.90                                                     Condition Corresponding Value (4)                                                                    0.39 (wide-angle end)                                                          0.20 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.68 (wide-angle end)                                                          0.82 (telephoto end)                                     Condition Corresponding Value (6)                                                                    1.51 (wide-angle end)                                                          1.48 (telephoto end)                                     __________________________________________________________________________

Table 47 below summarizes the numerical value data of the cams of the focusing lens unit in the fourth embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 46. Note that the meanings of the reference symbols in Table 47 are the same as those in the first embodiment.

                  TABLE 47                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Fourth                       Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)       F        ANGLE  (2)    F                                      ______________________________________                                         -9.0000                                                                               .9281     .0000                                                         -8.5000                                                                               .8963     .0000                                                         -8.0000                                                                               .8630     .0000                                                         -7.5000                                                                               .8282     .0000                                                         -7.0000                                                                               .7917     .0000                                                         -6.5000                                                                               .7533     .0000                                                         -6.0000                                                                               .7219     .0000                                                         -5.5000                                                                               .6702     .0000                                                         -5.0000                                                                               .6250     .0000                                                         -4.5000                                                                               .5773     .0000                                                         -4.000 .5269     .0000                                                         -3.5000                                                                               .4736     .0000                                                         -3.0000                                                                               .4173     .0000                                                         -2.5000                                                                               .3577     .0000                                                         -2.0000                                                                               .2945     .0000                                                         -1.5000                                                                               .2275     .0000                                                         -1.0000                                                                               .1564     .0000                                                         -.5000 .0806     .0000                                                         .0000  .0000     28.8000  .0000  .0000  28.8000                                .5000  -.0853    30.9500  .5000  .4528  30.9500                                1.0000 -.1755    33.1892  1.0000 .8955  33.1892                                1.5000 -.2715    35.5168  1.5000 1.3212 35.5168                                2.0000 -.3742    37.9389  2.0000 1.7245 37.9389                                2.5000 -.4847    40.4555  2.5000 2.0975 40.4555                                3.0000 -.6040    43.0624  3.0000 2.4333 43.0624                                3.5000 -.7333    45.7538  3.5000 2.7268 45.7538                                4.0000 -.8736    48.5235  4.0000 2.9752 48.5235                                4.5000 -1.0260   51.3658  4.5000 3.1782 51.3658                                5.0000 -1.1915   54.2940  5.0000 3.3456 54.2940                                5.5000 -1.3722   57.3528  5.5000 3.4940 57.3528                                6.0000 -1.5706   60.6006  6.0000 3.6376 60.6006                                6.5000 -1.7897   64.0869  6.5000 3.7892 64.0869                                7.0000 -2.0324   67.8574  7.0000 3.9608 67.8574                                7.5000 -2.3045   72.0128  7.5000 4.1657 72.0128                                8.0000 -2.6153   76.6717  8.0000 4.3908 76.6717                                8.5000 -2.9745   81.8893  8.5000 4.5944 81.8893                                9.0000 -3.3935   87.7449  9.0000 4.7514 87.7449                                9.5000 -3.8981   94.5847  9.5000 4.8913 94.5847                                10.0000                                                                               -4.5317   103.0000 10.0000                                                                               5.0874 103.0000                               ______________________________________                                    

The left table in Table 47 summarizes the numerical value data of the focus cam of the fourth embodiment, and the right table in Table 47 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 46.

Tables 48, 49, and 50 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=50.0), and the telephoto end (F=103.0) according to the second embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 48                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End (28.8 mm) in Fourth Embodiment                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               .043                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               .086                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               .143                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               .217                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               .443                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               .645                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               .928                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in Fourth                                                                  Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.280                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               -.007                                                                              2)                                                                               -.277                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               -.015                                                                              2)                                                                               -.274                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               -.025                                                                              2)                                                                               -.270                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               -.038                                                                              2)                                                                               -.264                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               -.084                                                                              2)                                                                               -.247                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               -.131                                                                              2)                                                                               -.232                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               -.209                                                                              2)                                                                               -.211                                                                              3)                                                                               -12.818                                                                            4)                                                                               .114                                          Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle                                                             End (28.8 mm) in Fourth Embodiment                                             R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.954                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               1.958                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               1.962                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               1.967                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               1.973                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               1.991                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               2.007                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               2.027                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in Fourth                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.166                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               -.161                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               -.156                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               -.148                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               -.139                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               -.113                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               -.091                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.062                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Asociated With Direction of Rotation      at Wide-angle End                                                              (28.8 mm) in Fourth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.324                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               -.316                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               -.306                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               -.292                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               -.275                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               -.225                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               -.182                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.127                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.04,         γ.sub.aR /γ.sub.a0 = 0.39                                    

                                      TABLE 49                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (50.0 mm) in Fourth Embodiment                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.258                                                                              1)                                                                               .000                                                                               2)                                                                               .077                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.527                                                                              1)                                                                               .000                                                                               2)                                                                               .154                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.905                                                                              1)                                                                               .000                                                                               2)                                                                               .257                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.413                                                                             1)                                                                               .000                                                                               2)                                                                               .385                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.230                                                                             1)                                                                               .000                                                                               2)                                                                               .770                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.226                                                                             1)                                                                               .000                                                                               2)                                                                               1.103                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.552                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Middle Position (50.0      mm) in Fourth                                                                  Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.366                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R 10.000                                                                             ANG                                                                               -.258                                                                              1)                                                                               -.007                                                                              2)                                                                               -.361                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R 5.000                                                                              ANG                                                                               -.527                                                                              1)                                                                               -.015                                                                              2)                                                                               -.355                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R 3.000                                                                              ANG                                                                               -.905                                                                              1)                                                                               -.025                                                                              2)                                                                               -.347                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R 2.000                                                                              ANG                                                                               -1.413                                                                             1)                                                                               -.039                                                                              2)                                                                               -.338                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R 1.000                                                                              ANG                                                                               -3.230                                                                             1)                                                                               -.086                                                                              2)                                                                               -.309                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R .700                                                                               ANG                                                                               -5.226                                                                             1)                                                                               -.135                                                                              2)                                                                               -.284                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               -.218                                                                              2)                                                                               -.251                                                                              3)                                                                               20.985                                                                             4)                                                                               -.092                                         Conversion Coefficient γ.sub.x Asociated With Direction of Optical       Axis at Middle                                                                 Position (50.0 mm) in Fourth Embodiment                                        R .000                                                                               ANG                                                                               -.000                                                                              1)                                                                               .000                                                                               2)                                                                               3.242                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.258                                                                              1)                                                                               .000                                                                               2)                                                                               3.258                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.527                                                                              1)                                                                               .000                                                                               2)                                                                               3.273                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.905                                                                              1)                                                                               .000                                                                               2)                                                                               3.294                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.413                                                                             1)                                                                               .000                                                                               2)                                                                               3.318                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.230                                                                             1)                                                                               .000                                                                               2)                                                                               3.388                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.226                                                                             1)                                                                               .000                                                                               2)                                                                               3.443                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R.                                                                               .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               3.510                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Middle Position (50.0 mm) in Fourth                Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.305                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.258                                                                              1)                                                                               .000                                                                               2)                                                                               -.292                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.527                                                                              1)                                                                               .000                                                                               2)                                                                               -.280                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.905                                                                              1)                                                                               .000                                                                               2)                                                                               -.263                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.413                                                                             1)                                                                               .000                                                                               2)                                                                               -.242                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.230                                                                             1)                                                                               .000                                                                               2)                                                                               -.187                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.226                                                                             1)                                                                               .000                                                                               2)                                                                               -.147                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.095                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Asociated With Direction of Rotation      at Middle Position                                                             (50.0 mm) in Fourth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.990                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.258                                                                              1)                                                                               .000                                                                               2)                                                                               -.953                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.527                                                                              1)                                                                               .000                                                                               2)                                                                               -.916                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.905                                                                              1)                                                                               .000                                                                               2)                                                                               -.866                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.413                                                                             1)                                                                               .000                                                                               2)                                                                               -.804                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.230                                                                             1)                                                                               .000                                                                               2)                                                                               -.632                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.226                                                                             1)                                                                               .000                                                                               2)                                                                               -.507                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.335                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.08,         γ.sub.aR /γ.sub.a0 = 0.34                                    

                                      TABLE 50                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End (103.0 mm) in Fourth Embodiment                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               .350                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               .669                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               1.057                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               1.496                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               2.611                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               3.414                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               4.356                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Telephoto End (103.0       mm) in Fourth                                                                  Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.652                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               -.007                                                                              2)                                                                               -.626                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               -.015                                                                              2)                                                                               -.602                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               -.025                                                                              2)                                                                               -.573                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               -.039                                                                              2)                                                                               -.541                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               -.087                                                                              2)                                                                               -.457                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               -.138                                                                              2)                                                                               -.397                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               -.228                                                                              2)                                                                               -.327                                                                              3)                                                                               10.590                                                                             4)                                                                               -.212                                         Conversion Coefficient γ.sub.x Asociated With Direction of Optical       Axis at Telephoto End                                                          (103.0 mm) in Fourth Embodiment                                                R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               2.883                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               3.051                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               3.198                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               3.368                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               3.552                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               3.968                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               4.225                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               4.481                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Telephoto End (103.0 mm) in Fourth                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -1.449                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               -1.253                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               -1.101                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               -.944                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000                                                                               2)                                                                               -.791                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               -.488                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               -.333                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.186                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Asociated With Direction of Rotation      at Telephoto End                                                               (103.0 mm) in Fourth Embodiment                                                R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -4.179                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.260                                                                              1)                                                                               .000                                                                               2)                                                                               -3.823                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.532                                                                              1)                                                                               .000                                                                               2)                                                                               -3.520                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -.912                                                                              1)                                                                               .000                                                                               2)                                                                               -3.180                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -1.421                                                                             1)                                                                               .000)                                                                              2)                                                                               -2.810                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.000                                                                              ANG                                                                               -3.223                                                                             1)                                                                               .000                                                                               2)                                                                               -1.935                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R .700                                                                               ANG                                                                               -5.217                                                                             1)                                                                               .000                                                                               2)                                                                               -1.406                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R .500                                                                               ANG                                                                               -9.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.833                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.55,         γ.sub.aR /γ.sub.a0 = 0.20                                    

As can be seen from Tables 48, 49, and 50, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

From Tables 48, 49, and 50, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.39 at the wide-angle end (F=28.8), ×0.34 at the middle position (F=50.0), and ×0.20 at the telephoto end (F=103.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the fourth embodiment is calculated using formula (a), and is compared with that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

When the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0

    N.sub.W >11.2 N.sub.M >11.2 N.sub.T >8.3

Fourth Embodiment

    N.sub.W >5.1 N.sub.M >5.9 N.sub.T >8.9

Therefore, it can be seen that the numbers of divisions become small, compared to those in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

As described above, in the fourth embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is smaller than that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 51, 52, and 53 summarize the calculation results of the values of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=28.8), middle position (F=50.0), and telephoto end (F=103.0) according to the fourth embodiment.

The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 51, 52, and 53, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 42, 43, and 44, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.5, -9.0), and it indicates that this position corresponds to the closest in-focus (R=0.5 m) corresponding position.

                                      TABLE 51                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (28.8 mm) in Fourth Embodiment         F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.260                                                                              5.000                                                                              -.532                                                                              3.000                                                                              -.912                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.324                                                                              .000    -.319   -.313   -.305                                       2  10.000  -.321                                                                              -.316                                                                              .000    -.310   -.301                                       3  5.000   -.317   -.312                                                                              -.306                                                                              .000    -.297                                       4  3.000   -.312   -.306   -.300                                                                              -.292                                                                              .000                                        5  2.000   -.304   -.298   -.293   -.285                                       6  1.000   -.280   -.275   -.269   -.262                                       7  .700    -.257   -.252   -.247   -.240                                       8  .500    -.220   -.216   -.211   -.206                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               7.61                                                                               -.17                                                                               6.62                                                                               -.28                                                                               6.11                                        2  10.000                                                                             .08 8.40                                                                               .00 .00 -.08                                                                               6.25                                                                               -.20                                                                               5.98                                        3  5.000                                                                              .17 7.80                                                                               .08 6.82                                                                               .00 .00 -.11                                                                               5.99                                        4  3.000                                                                              .28 7.26                                                                               .20 6.48                                                                               .11 6.05                                                                               .00 .00                                         5  2.000                                                                              .43 6.98                                                                               .35 6.41                                                                               .26 6.15                                                                               .15 6.11                                        6  1.000                                                                              .90 6.66                                                                               .81 6.33                                                                               .73 6.15                                                                               .61 6.00                                        7  .700                                                                               1.34                                                                               6.48                                                                               1.25                                                                               6.22                                                                               1.16                                                                               6.05                                                                               1.03                                                                               5.88                                        8  .500                                                                               1.98                                                                               6.18                                                                               1.89                                                                               5.98                                                                               1.79                                                                               5.82                                                                               1.66                                                                               5.63                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.421                                                                             1.000                                                                              -3.223                                                                             .700                                                                               -5.217                                                                             .500                                                                               -9.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.295   -.262   -.234   -.192                                       2  10.000  -.291   -.259   -.231   -.190                                       3  5.000   -.287   -.256   -.228   -.187                                       4  3.000   -.282   -.251   -.223   -.183                                       5  2.000                                                                              -.275                                                                              .000    -.245   -.218   -.179                                       6  1.000   -.253                                                                              -.225                                                                              .000    -.200   -.163                                       7  .700    -.232   -.206                                                                              -.182                                                                              .000    -.148                                       8  .500    -.198   -.175   -.154                                                                              -.127                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.42                                                                               5.88                                                                               -.85                                                                               5.09                                                                               -1.22                                                                              4.27                                                                               -1.73                                                                              3.33                                        2  10.000                                                                             -.34                                                                               5.83                                                                               -.77                                                                               5.08                                                                               -1.14                                                                              4.25                                                                               -1.66                                                                              3.33                                        3  5.000                                                                              -.26                                                                               5.85                                                                               -.69                                                                               5.07                                                                               -1.07                                                                              4.24                                                                               -1.58                                                                              3.32                                        4  3.000                                                                              -.14                                                                               5.84                                                                               -.58                                                                               5.05                                                                               -.96                                                                               4.22                                                                               -1.48                                                                              3.31                                        5  2.000                                                                              .00 .00 -.44                                                                               5.03                                                                               -.83                                                                               4.19                                                                               -1.35                                                                              3.30                                        6  1.000                                                                              .46 5.74                                                                               .00 .00 -.40                                                                               4.05                                                                               -.94                                                                               3.27                                        7  .700                                                                               .88 5.62                                                                               .41 4.77                                                                               .00 .00 -.56                                                                               3.31                                        8  .500                                                                               1.50                                                                               5.37                                                                               1.01                                                                               4.54                                                                               .58 3.83                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.68, K.sub.aR      /γ.sub.aR = 1.51                                                   

                                      TABLE 52                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (50.0 mm) in Fourth Embodiment        F = 50.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.258                                                                              5.000                                                                              -.527                                                                              3.000                                                                              -.905                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.989                                                                              .000    -.964   -.938   -.904                                       2  10.000  -.979                                                                              -.953                                                                              .000    -.927   -.893                                       3  5.000   -.967   -.941                                                                              -.915                                                                              .000    -.882                                       4  3.000   -.950   -.925   -.900                                                                              -.866                                                                              .000                                        5  2.000   -.929   -.903   -.878   -.845                                       6  1.000   -.855   -.832   -.808   -.777                                       7  .700    -.791   -.769   -.747   -.719                                       8  .500    -.686   -.667   -.648   -.623                                       __________________________________________________________________________     PQS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.25                                                                               21.45                                                                              -.49                                                                               20.06                                                                              -.82                                                                               18.89                                       2  10.000                                                                             .25 23.31                                                                              .00 .00 -.25                                                                               19.46                                                                              -.58                                                                               18.67                                       3  5.000                                                                              .51 22.59                                                                              .25 20.95                                                                              .00 .00 -.33                                                                               18.53                                       4  3.000                                                                              .86 21.97                                                                              .60 20.56                                                                              .34 19.74                                                                              .00 .00                                         5  2.000                                                                              1.31                                                                               21.37                                                                              1.04                                                                               20.12                                                                              .78 19.19                                                                              .43 17.69                                       6  1.000                                                                              2.76                                                                               20.39                                                                              2.47                                                                               19.42                                                                              2.18                                                                               18.63                                                                              1.81                                                                               17.58                                       7  .700                                                                               4.13                                                                               20.60                                                                              3.82                                                                               19.80                                                                              3.51                                                                               19.13                                                                              3.11                                                                               18.29                                       8  .500                                                                               6.17                                                                               20.14                                                                              5.83                                                                               19.41                                                                              5.49                                                                               18.77                                                                              5.04                                                                               17.95                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.413                                                                             1.000                                                                              -3.230                                                                             .700                                                                               -5.226                                                                             .500                                                                               -9.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.861   -.735   -.637   -.506                                       2  10.000  -.850   -.726   -.629   -.500                                       3  5.000   -.839   -.716   -.621   -.493                                       4  3.000   -.824   -.703   -.609   -.484                                       5  2.000                                                                              -.804                                                                              .000    -.685   -.595   -.472                                       6  1.000   -.739                                                                              -.632                                                                              .000    -.551   -.435                                       7  .700    -.684   -.588                                                                              -.507                                                                              .000    -.397                                       8  .500    -.592   -.506   -.433                                                                              -.335                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -1.22                                                                              17.17                                                                              -2.37                                                                              14.61                                                                              -3.33                                                                              13.01                                                                              -4.56                                                                              8.91                                        2  10.000                                                                             -.98                                                                               16.98                                                                              -2.16                                                                              14.60                                                                              -3.13                                                                              13.02                                                                              -4.37                                                                              8.88                                        3  5.000                                                                              -.74                                                                               16.81                                                                              -1.94                                                                              14.62                                                                              -2.92                                                                              13.04                                                                              -4.18                                                                              8.85                                        4  3.000                                                                              -.42                                                                               16.58                                                                              -1.63                                                                              14.68                                                                              -2.63                                                                              13.07                                                                              -3.92                                                                              8.81                                        5  2.000                                                                              .00 .00 -1.25                                                                              14.86                                                                              -2.27                                                                              13.12                                                                              -3.58                                                                              8.75                                        6  1.000                                                                              1.34                                                                               16.67                                                                              .00 .00 -1.11                                                                              12.70                                                                              -2.51                                                                              8.43                                        7  .700                                                                               2.61                                                                               17.58                                                                              1.17                                                                               16.71                                                                              .00 .00 -1.50                                                                              8.12                                        8  .500                                                                               4.49                                                                               17.09                                                                              2.92                                                                               14.54                                                                              1.63                                                                               11.09                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.69, K.sub.aR      /γ.sub.aR = 1.51                                                   

                                      TABLE 53                                     __________________________________________________________________________     Conversion Coefficient K.sub.a : (rs), γ.sub.a : (r) Associated          with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (103.0 mm) in Fourth Embodiment         F = 103.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.260                                                                              5.000                                                                              -.532                                                                              3.000                                                                              -.912                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -4.180                                                                             .000    -3.855  -3.573  -3.259                                      2  10.000  -4.152                                                                             -3.8l9                                                                             .000    -3.543  -3.233                                      3  5.000   -4.121  -3.794                                                                             -3.520                                                                             .000    -3.213                                      4  3.000   -4.091  -3.767  -3.495                                                                             -3.180                                                                             .000                                        5  2.000   -4.050  -3.726  -3.451  -3.135                                      6  1.000   -3.907  -3.578  -3.301  -2.986                                      7  .700    -3.747  -3.416  -3.139  -2.827                                      8  .500    -3.440  -3.112  -2.841  -2.540                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -1.02                                                                              106.64                                                                             -1.90                                                                              127.23                                                                             -2.97                                                                              120.34                                      2  10.000                                                                             1.08                                                                               164.84                                                                             .00 .00 -.96                                                                               151.92                                                                             -2.11                                                                              126.78                                      3  5.000                                                                              2.19                                                                               156.83                                                                             1.03                                                                               152.81                                                                             .00 .00 -1.22                                                                              119.67                                      4  3.000                                                                              3.73                                                                               176.52                                                                             2.46                                                                               179.24                                                                             1.33                                                                               184.76                                                                             .00 .00                                         5  2.000                                                                              5.76                                                                               186.20                                                                             4.33                                                                               176.43                                                                             3.07                                                                               156.05                                                                             1.60                                                                               113.27                                      6  1.000                                                                              12.59                                                                              192.95                                                                             10.60                                                                              168.02                                                                             8.88                                                                               142.43                                                                             6.90                                                                               113.06                                      7  .700                                                                               19.55                                                                              189.03                                                                             16.94                                                                              160.55                                                                             14.71                                                                              135.70                                                                             12.17                                                                              109.62                                      8  .500                                                                               30.96                                                                              175.08                                                                             27.20                                                                              146.97                                                                             24.06                                                                              124.62                                                                             20.54                                                                              102.06                                      __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.421                                                                             1.000                                                                              -3.223                                                                             .700                                                                               -5.217                                                                             .500                                                                               -9.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -2.926  -2.181  -1.718  -1.232                                      2  10.000  -2.902  -2.160  -1.700  -1.218                                      3  5.000   -2.880  -2.140  -1.682  -1.203                                      4  3.000   -2.847  -2.111  -1.657  -1.183                                      5  2.000                                                                              -2.810                                                                             .000    -2.073  -1.624  -1.157                                      6  1.000   -2.659                                                                             -1.934                                                                             .000    -1.514  -1.069                                      7  .700    -2.506  -1.815                                                                             -1.406                                                                             .000    -.981                                       8  .500    -2.234  -1.590  -1.214                                                                             -.833                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -4.16                                                                              100.97                                                                             -7.03                                                                              55.12                                                                              -8.96                                                                              40.47                                                                              -11.09                                                                             23.17                                       2  10.000                                                                             -3.37                                                                              103.32                                                                             -6.40                                                                              54.80                                                                              -8.43                                                                              40.38                                                                              -10.65                                                                             23.07                                       3  5.000                                                                              -2.56                                                                              103.11                                                                             -5.76                                                                              54.22                                                                              -7.88                                                                              40.24                                                                              -10.19                                                                             22.96                                       4  3.000                                                                              -1.45                                                                              109.95                                                                             -4.88                                                                              53.47                                                                              -7.13                                                                              40.09                                                                              -9.57                                                                              22.80                                       5  2.000                                                                              .00 .00 -3.73                                                                              52.11                                                                              -6.16                                                                              39.89                                                                              -8.77                                                                              22.60                                       6  1.000                                                                              4.79                                                                               89.05                                                                              .00 .00 -3.02                                                                              39.55                                                                              -6.18                                                                              21.85                                       7  .700                                                                               9.51                                                                               87.85                                                                              3.62                                                                               58.52                                                                              .00 .00 -3.71                                                                              20.98                                       8  .500                                                                               16.93                                                                              82.65                                                                              9.19                                                                               51.65                                                                              4.59                                                                               33.50                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.82, K.sub.aR      /γ.sub.aR = 1.48                                                   

As calculation results of the rate of change of K_(a) with respect to .sub.γ av at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the fourth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.90 are as follows.

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            3.47           0.40                                                 (F = 28.8)                                                                     Middle Position                                                                           4.09           0.39                                                 (F = 50.0)                                                                     Telephoto End                                                                             4.98           0.39                                                 (F = 103.0)                                                                    Fourth Embodiment                                                              Wide-angle End                                                                            0.68           1.51                                                 (F = 28.8)                                                                     Middle Position                                                                           0.69           1.51                                                 (F = 50.0)                                                                     Telephoto End                                                                             0.82           1.48                                                 (F = 103.0)                                                                    ______________________________________                                    

As described above, in the fourth embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the fourth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.90, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -7.4%         -12.2%                                               (F = 28.8)                                                                     Middle Position                                                                           -18.4%         -12.1%                                               (F = 50.0)                                                                     Telephoto End                                                                             -20.2%         -13.4%                                               (F = 103.0)                                                                    Fourth Embodiment                                                              Wide-angle End                                                                             -5.2%         -0.6%                                                (F = 28.8)                                                                     Middle Position                                                                           -2.5%          -0.3%                                                (F = 50.0)                                                                     Telephoto End                                                                             -1.3%          -0.5%                                                (F = 103.0)                                                                    ______________________________________                                    

As described above, in the fourth embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 54 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 46) of the fourth embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 54 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.0, 0.7, and 0.5 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 70.0, 85.0, and 103.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 54                                     __________________________________________________________________________     Displament Amount Bf (mm) of Imaging Point and Amount DX                       (mm) of Movement for Focusing in Fourth Embodiment                             __________________________________________________________________________             0.50 m                                                                             0.70 m                                                                               1.00 m                                                                             2.00 m                                                                               3.00 m                                                                             5.00 m                                         __________________________________________________________________________     F 28.800 Bf                                                                            .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           F 3S.000 Bf                                                                            .000                                                                               -.001 .001                                                                               .005  .005                                                                               .003                                           F 50.000 Bf                                                                            .000                                                                               .004  .005                                                                               -.006 -.006                                                                              -.004                                          F 70.000 Bf                                                                            .000                                                                               -.005 -.011                                                                              -.001 .002                                                                               .003                                           F 85.000 Bf                                                                            .000                                                                               -.015 -.009                                                                              -.014 -.013                                                                              -.007                                          F 103.000 Bf                                                                           .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           __________________________________________________________________________     ANGLE DA                                                                               -9.000                                                                              -5.217                                                                             -3.223                                                                               -1.421                                                                              -.912                                                                              -.532                                          __________________________________________________________________________     F 28.800 DX                                                                            .000 .928                                                                               .000  .000                                                                              R .0.50 m                                            F 35.000 DX                                                                            .000 1.086                                                                              .000  .000                                                                              R 0.50 m                                             F 50.000 DX                                                                            .000 1.552                                                                              .000  .000                                                                              R 0.50 m                                             F 70.000 DX                                                                            .000 2.432                                                                              .000  .000                                                                              R 0.50 m                                             F 85.000 DX                                                                            .000 3.232                                                                              .000  .000                                                                              R 0.50 m                                             F 103.000 DX                                                                           .000 4.356                                                                              .000  .000                                                                              R 0.50 m                                             F 28.800 DX                                                                            .000 .645                                                                               .000  .000                                                                              R 0.70 m                                             F 35.000 DX                                                                            .000 .759                                                                               .000  .000                                                                              R 0.70 m                                             F 50.000 DX                                                                            .000 1.102                                                                              .000  .000                                                                              R 0.70 m                                             F 70.000 DX                                                                            .000 1.788                                                                              .000  .000                                                                              R 0.70 m                                             F 85.000 DX                                                                            .000 2.447                                                                              .000  .000                                                                              R 0.70 m                                             F 103.000 DX                                                                           .000 3.414                                                                              .000  .000                                                                              R 0.70 m                                             F 28.800 DX                                                                            .000 .443                                                                               .000  .000                                                                              R 1.00 m                                             F 35.000 DX                                                                            .000 .522                                                                               .000  .000                                                                              R 1.00 m                                             F 50.000 DX                                                                            .000 .769                                                                               .000  .000                                                                              R 1.00 m                                             F 70.000 DX                                                                            .000 1.286                                                                              .000  .000                                                                              R 1.00 m                                             F 85.000 DX                                                                            .000 1.804                                                                              .000  .000                                                                              R 1.00 m                                             F 103.000 DX                                                                           .000 2.611                                                                              .000  .000                                                                              R 1.00 m                                             F 28.800 DX                                                                            .000 .217                                                                               .000  .000                                                                              R 2.00 m                                             F 35.000 DX                                                                            .000 .255                                                                               .000  .000                                                                              R 2.00 m                                             F 50.000 DX                                                                            .000 .387                                                                               .000  .000                                                                              R 2.00 m                                             F 70.000 DX                                                                            .000 .666                                                                               .000  .000                                                                              R 2.00 m                                             F 85.000 DX                                                                            .000 .975                                                                               .000  .000                                                                              R 2.00 m                                             F 103.000 DX                                                                           .000 1.496                                                                              .000  .000                                                                              R 2.00 m                                             F 28.800 DX                                                                            .000 .143                                                                               .000  .000                                                                              R 3.00 m                                             F 35.000 DX                                                                            .000 .169                                                                               .000  .000                                                                              R 3.00 m                                             F 5 0.000 DX                                                                           .000 .258                                                                               .000  .000                                                                              R 3.00 m                                             F 70.000 DX                                                                            .000 .449                                                                               .000  .000                                                                              R 3.00 m                                             F 85.000 DX                                                                            .000 .670                                                                               .000  .000                                                                              R 3.00 m                                             F 103.000 DX                                                                           .000 1.057                                                                              .000  .000                                                                              R 3.00 m                                             F 28.800 DX                                                                            .000 .086                                                                               .000  .000                                                                              R 5.00 m                                             F 35.000 DX                                                                            .000 .100                                                                               .000  .000                                                                              R 5.00 m                                             F 50.000 DX                                                                            .000 .155                                                                               .000  .000                                                                              R 5.00 m                                             F 70.000 DX                                                                            .000 .272                                                                               .000  .000                                                                              R 5.00 m                                             F 85.000 DX                                                                            .000 .412                                                                               .000  .000                                                                              R 5.00 m                                             F 103.000 DX                                                                           .000 .669                                                                               .000  .000                                                                              R 5.00 m                                             __________________________________________________________________________

As can be seen from Table 54, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Fifth Embodiment!

A zoom lens of the fifth embodiment is a zoom lens which has a five-unit arrangement, i.e., positive, negative, positive, negative and positive lens units, and attains focusing by a negative fourth lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.80 m) to the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=126.0) is set to be -0.55.

Table 55 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the fifth embodiment.

The upper table in Table 55 summarizes the focal lengths data, and principal point interval data of the respective lens units of the optical system corresponding to the fifth embodiment.

In this table, F1, F2, F3, F4 and F5 are respectively the focal lengths of first, second, third, fourth, and fifth lens units, and D1, D2, D3, D4, and D5 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, and the principal point interval between the fourth and fifth lens unit, and the principal point interval between the fifth lens unit and a predetermined imaging plane in six zooming states (F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 70.0 (4-POS), 95.0 mm (5-POS), and 126.0 mm (6-POS)).

The middle table in Table 55 summarizes spline sample data when the shape (a curve g_(2F) in FIG. 3) of the focus cam in the fourth lens unit of the fifth embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 55 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=28.8, 35.0, 50.0, 70.0, 95.0, and 126.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) using the focus cam of the fifth embodiment. In the lower table in Table 55, since the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=126.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.80 m) is set to be -5.5, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the first embodiment is -0.55.

                                      TABLE 55                                     __________________________________________________________________________     Fifth Embodiment F = 28.8 to 126.0 (Rotation Amount Ratio: a.sub.F             /a.sub.Z = -0.55)                                                              __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Fifth             Embodiment                                                                               1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                              6-POS                                          __________________________________________________________________________            F  28.8000                                                                            35.0000                                                                             50.0000                                                                            70.0000                                                                             95.0000                                                                            126.0000                                       F1                                                                               98.0000                                                                             D1 9.3696                                                                             15.5678                                                                             26.0774                                                                            35.1343                                                                             42.9607                                                                            49.3378                                        F2                                                                               -20.2000                                                                            D2 34.5121                                                                            30.5093                                                                             24.1872                                                                            19.0594                                                                             14.7856                                                                            10.6994                                        F3                                                                               21.3000                                                                             D3 8.9319                                                                             9.5307                                                                              10.6727                                                                            11.7442                                                                             12.4611                                                                            13.1911                                        F4                                                                               -19.6000                                                                            D4 14.4820                                                                            13.8832                                                                             12.7412                                                                            11.6697                                                                             10.9528                                                                            10.2228                                        F5                                                                               35.5000                                                                             D5 49.8013                                                                            51.5975                                                                             55.0237                                                                            58.2383                                                                             61.1451                                                                            63.0195                                        __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding to           Fifth                                                                          Embodiment                                                                          ANGLE                                                                               (1)    (2)                                                                               (3)    (4) (5)                                             __________________________________________________________________________     1    -10.0000                                                                            .0000  .0000                                                                             .0000  -.4328                                                                             .0000                                           2    -5.5000                                                                             .0000  .0000                                                                             .0000  -.3653                                                                             .0000                                           3    -3.3884                                                                             .0000  .0000                                                                             .0000  -.2845                                                                             .0000                                           4    -1.7882                                                                             .0000  .0000                                                                             .0000  -.1832                                                                             .0000                                           6    .7550                                                                               .0000  .0000                                                                             .0000  -.0886                                                                             .0000                                           7    .4267                                                                               .0000  .0000                                                                             .0000  -.0524                                                                             .0000                                           8    .0000                                                                               .0000  .0000                                                                             .0000  .0000                                                                              .0000                                           9    .5000                                                                               .0000  .0000                                                                             .0000  .0720                                                                              .0000                                           10   4.5000                                                                              .0000  .0000                                                                             .0000  1.1810                                                                             .0000                                           11   6.0000                                                                              .0000  .0000                                                                             .0000  2.0800                                                                             .0000                                           12   6.6116                                                                              .0000  .0000                                                                             .0000  2.5920                                                                             .0000                                           13   8.2118                                                                              .0000  .0000                                                                             .0000  4.3577                                                                             .0000                                           14   8.7719                                                                              .0000  .0000                                                                             .0000  5.1954                                                                             .0000                                           15   9.2450                                                                              .0000  .0000                                                                             .0000  6.0053                                                                             .0000                                           16   9.5733                                                                              .0000  .0000                                                                             .0000  6.6341                                                                             .0000                                           17   10.0000                                                                             .0000  .0000                                                                             .0000  7.5475                                                                             .0000                                           18   11.0000                                                                             .0000  .0000                                                                             .0000  10.1892                                                                            .0000                                           __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Fifth Embodiment                                                               (Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.55)                              __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal Length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     28.8 mm        .0000  5.00 m    -.427                                          35.0 mm        1.3439                                                                                3.00 m    -.755                                          50.0 mm        3.8037                                                                                2.00 m    -1.228                                         70.0 mm        6.0180                                                                                1.50 m    -1.788                                         95.0 mm        8.0481                                                                                1.00 m    -3.388                                         126.0 mm       10.0000                                                                               0.80 m    -5.500                                         Condition Corresponding Value (1)                                                                    1.31                                                     Condition Corresponding Value (2)                                                                    17.44                                                    Condition Corresponding Value (3)                                                                   -0.55                                                     Condition Corresponding Value (4)                                                                    0.21 (wide-angle end)                                                          0.26 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.50 (wide-angle end)                                                          0.56 (telephoto end)                                     Condition Corresponding Value (6)                                                                    2.39 (wide-angle end)                                                          2.00 (telephoto end)                                     __________________________________________________________________________

Table 56 below summarizes the numerical value data of the cams of the focusing lens unit in the fifth embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 55. In this table (ANGLE) is the angle of rotation of the rotatable lens barrel, (2) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 56                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Fifth                        Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (4)       F        ANGLE  (4)    F                                      ______________________________________                                         -5.5000                                                                               -.3653    .0000                                                         -5.0000                                                                               -.3503    .0000                                                         -4.5000                                                                               -.3329    .0000                                                         -4.0000                                                                               -.3129    .0000                                                         -3.5000                                                                               -.2900    .0000                                                         -3.0000                                                                               -.2640    .0000                                                         -2.5000                                                                               -.2341    .0000                                                         -2.0000                                                                               -.1995    .0000                                                         -1.5000                                                                               -.1593    .0000                                                         -1.0000                                                                               -.1134    .0000                                                         -.5000 -.0608    .0000                                                         .0000  .0000     28.8000  .0000  .0000  28.8000                                .5000  .0720     31.0285  .5000  .3775  31.0285                                1.0000 .1527     33.3443  1.0000 .7403  33.3443                                1.5000 .2437     35.7763  1.5000 1.0933 35.7763                                2.0000 .3482     38.3954  2.0000 1.4434 38.3954                                2.5000 .4691     41.2540  2.5000 1.7885 41.2540                                3.0000 .6098     44.3801  3.0000 2.1201 44.3801                                3.5000 .7732     47.7884  3.5000 2.4272 47.7884                                4.0000 .9626     51.4883  4.0000 2.6982 51.4883                                4.5000 1.1810    55.4931  4.5000 2.9324 55.4931                                5.0000 1.4331    59.8203  5.0000 3.1395 59.8203                                5.5000 1.7289    64.5708  5.5000 3.3332 64.5708                                6.0000 2.0800    69.8013  6.0000 3.5238 69.8013                                6.5000 2.4927    75.5383  6.5000 3.7167 75.5383                                7.0000 2.9552    81.4767  7.0000 3.8432 81.4767                                7.5000 3.4759    87.6730  7.5000 3.8489 87.6730                                8.0000 4.0752    94.3296  8.0000 3.7003 94.3296                                8.5000 4.7727    101.5681 8.5000 3.3763 101.5681                               9.0000 5.5729    109.2585 9.0000 2.8865 109.2585                               9.5000 6.4888    117.3718 9.5000 2.2362 117.3718                               10.0000                                                                               7.5475    126.0000 10.0000                                                                               1.4115 126.0000                               ______________________________________                                    

The left table in Table 56 summarizes the numerical value data of the focus cam of the fifth embodiment, and the right table in Table 56 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (4) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus (a curve g₄ in FIG. 3) of the fourth lens unit calculated using the paraxial data in the upper table in Table 55.

Therefore, the zoom compensation cam (a curve g_(4H) in FIG. 3) is determined by subtracting the focus cam (the curve g_(4F) in FIG. 3) from the movement locus (the curve g₄ in FIG. 3) upon zooming of the fourth lens unit determined by the paraxial data in the upper table in Table 55.

FIG. 3 and FIG. 4 will be briefly described below.

FIG. 3 shows the paraxial arrangement and the movement loci upon zooming of the zoom lens according to the fifth embodiment, and FIG. 3 shows the shapes of the focus cam and the zoom compensation cam of the fourth lens unit of this embodiment. Referring to FIG. 1, G1, G2, G3, G4, and G5 respectively represent the first, second, third, fourth, and fifth lens units, and g₁, g₂, g₃, g₄ and g₅ respectively represent the movement loci upon zooming of the first, second, third, fourth, and fifth lens units. In addition, g_(4F) and g_(4H) respectively represent the shapes of the focus cam and the zoom compensation cam of the fourth lens unit. As described above, a shape obtained by synthesizing the focus cam g_(4F) and the zoom compensation cam g_(4H) of the fourth lens unit coincides with the movement locus g₄ of the fourth lens unit.

FIG. 4 is a view for explaining the shape of the focus cam g₄ F of the fifth embodiment. Referring to FIG. 4, (F=28.8; R=un) and (F=28.8; R=0.80) respectively represent the in-focus positions at the infinity and the closest distance (R=0.80 m) at the wide-angle end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(0; 0) and (x; a)=(-0.363; -5.5). On the other hand, (F=126; R=un) and (F=126; R=0.80) respectively represent the in-focus positions at the infinity and the closest distance (R=0.80 m) at the telephoto end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(7.548; 10) and (x; a)=(1.181; 4.5).

Upon zooming from the wide-angle end to the telephoto end, the fourth lens unit moves on the focus cam g_(4F) from the coordinate position (0; 0) to the coordinate position (7.548; 10) for an infinity object, and from the coordinate position (-0.365; -5.5) to the coordinate position (1.181; 4.5) for a closest distance object. Therefore, the fourth lens unit moves by 10.0 in the direction of rotation (the direction of an axis a) in both the cases. On the other hand, upon focusing from the infinity arrangement to the closest distance object, the fourth lens unit moves on the focus cam g_(4F) from the coordinate position (0; 0) to the coordinate position (-0.365; -5.5) at the wide-angle end, and from the coordinate position (7.548; 10) to the coordinate position (1.181; 4.5) at the telephoto end. Therefore, the fourth lens unit moves by -5.5 in the direction of rotation (the direction of the axis a) at these ends. In contrast to this, in the direction of the optical axis (the direction of an axis x), the fourth lens unit moves by -0.365 at the wide-angle end, and by -6.367 at the telephoto end.

Since the shape of the focus cam g_(4F) is determined by interpolating the coordinates (F=28.8; R=0.80), (F=28.8; R=un), (F=126; R=0.80), and (F=126; R=un) by the spline function, the change in slope (dx/da) of the focus cam g_(4F) becomes larger as the absolute value of the x-coordinate of (F=28.8; R=0.80) is smaller or as the absolute value of the x-coordinate of (F=126; R=un) is larger. More specifically, as the ratio (Δx_(TR) /Δx_(WR)) between the amounts Δx_(TR) and Δx_(WR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end or telephoto end is larger, the change in slope (dx/da) of the focus cam becomes larger.

Tables 57, 58, and 59 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=70.0), and the telephoto end (F=126.0) according to the first embodiment, respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), 4), and 5) on the right side respectively represent the first, second, third, fourth, and fifth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(K) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0 and 0.80 m).

                                      TABLE 57                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle                                                                     End (28.8 mm) in Fifth Embodiment                                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.026                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.052                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.089                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.135                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.183                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.284                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.365                                                                              5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Wide-angle End (28.8       mm) in Fifth Embodiment                                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.295                                                                              3)                                                                               -.541                                                                              4)                                                                               -4.568                                                                             5)                                                                               -.403                                   R 10.000                                                                             ANG                                                                               -.204                                                                              1)                                                                               -.010                                                                              2)                                                                               -.291                                                                              3)                                                                               -.542                                                                              4)                                                                               -4.570                                                                             5).                                                                              -.403                                   R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               -.020                                                                              2)                                                                               -.287                                                                              3)                                                                               -.543                                                                              4)                                                                               -4.571                                                                             5)                                                                               -.403                                   R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               -.035                                                                              2)                                                                               -.281                                                                              3)                                                                               -.545                                                                              4)                                                                               -4.573                                                                             5)                                                                               -.403                                   R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               -.055                                                                              2)                                                                               -.274                                                                              3)                                                                               -.547                                                                              4)                                                                               -4.575                                                                             5)                                                                               -.403                                   R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               -.076                                                                              2)                                                                               -.266                                                                              3)                                                                               -.549                                                                              4)                                                                               -4.578                                                                             5)                                                                               -.403                                   R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               -.125                                                                              2)                                                                               -.250                                                                              3)                                                                               -.554                                                                              4)                                                                               -4.583                                                                             5)                                                                               -.403                                   R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               -.168                                                                              2)                                                                               -.238                                                                              3)                                                                               -.557                                                                              4)                                                                               -4.587                                                                             5)                                                                               -.403                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle End                                                         (28.8 mm) in Fifth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.225                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.227                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.229                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.231                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.235                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.239                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.246                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.252                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Wide-angle End (28.8 mm) in Fifth Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .133                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .123                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .115                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .105                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .092                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .079                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .050                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .028                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (28.8 mm) in Fifth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.428                                                                              5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.204                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.397                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.371                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.339                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.299                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.257                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .900                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.163                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.090                                                                              5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.01,         γ.sub.aR /γ.sub.a0 = 0.21                                    

                                      TABLE 58                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (70.0 mm) in Fifth Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.196                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.146                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.410                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.294                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.496                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.195                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.754                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.756                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.021                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.344                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.578                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.019                                                                             5)                                                                               .000                                    Imaging Magnification β.sub.K of Lens Units at Middle Position (70.0      mm) in Fifth Embodiment                                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.473                                                                              3)                                                                               -.774                                                                              4)                                                                               -3.044                                                                             5)                                                                               -.641                                   R 10.000                                                                             ANG                                                                               -.196                                                                              1)                                                                               -.010                                                                              2)                                                                               -.463                                                                              3)                                                                               -.780                                                                              4)                                                                               -3.051                                                                             5)                                                                               -.641                                   R 5.000                                                                              ANG                                                                               -.410                                                                              1)                                                                               -.021                                                                              2)                                                                               -.452                                                                              3)                                                                               -.786                                                                              4)                                                                               -3.059                                                                             5)                                                                               -.641                                   R 3.000                                                                              ANG                                                                               -.729                                                                              1)                                                                               -.035                                                                              2)                                                                               -.438                                                                              3)                                                                               -.795                                                                              4)                                                                               -3.069                                                                             5)                                                                               -.641                                   R 2.000                                                                              ANG                                                                               -1.195                                                                             1)                                                                               -.055                                                                              2)                                                                               -.420                                                                              3)                                                                               -.806                                                                              4)                                                                               -3.082                                                                             5)                                                                               -.641                                   R 1.500                                                                              ANG                                                                               -1.756                                                                             1)                                                                               -.077                                                                              2)                                                                               -.402                                                                              3)                                                                               -.817                                                                              4)                                                                               -3.096                                                                             5)                                                                               -.641                                   R 1.000                                                                              ANG                                                                               -3.344                                                                             1)                                                                               -.128                                                                              2)                                                                               -.366                                                                              3)                                                                               -.840                                                                              4)                                                                               -3.124                                                                             5)                                                                               -.641                                   R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               -.173                                                                              2)                                                                               -.339                                                                              3)                                                                               -.859                                                                              4)                                                                               -3.147                                                                             5)                                                                               -.641                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle Position                                                        (70.0 mm) in Fifth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.390                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.196                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.409                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.410                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.428                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.454                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.195                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.487                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.756                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.521                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.344                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.594                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.652                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Middle Position (70.0 m) in Fifth Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .770                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.196                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .719                                                                               5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.410                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .668                                                                               5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .599                                                                               5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.195                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .514                                                                               5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.756                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .438                                                                               5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.344                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .275                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .154                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position                                                    (70.0 mm) in Fifth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.611                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.196                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.452                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.410                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.288                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.729                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.067                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.195                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.794                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.756                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.542                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.344                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.987                                                                              5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.562                                                                              5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.08,         γ.sub.aR /γ.sub.a0 = 0.22                                    

                                      TABLE 59                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End                                                                  (126.0 mm) in Fifth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                                                               5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.203                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.452                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -.913                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -1.542                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.352                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.190                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.956                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -6.367                                                                             5)                                                                               .000                                    Imaging Magnification β.sub.x of Lens Units at Telephoto End (126.0       mm) in Fifth Embodiment                                                        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               -.000                                                                              2)                                                                               -.710                                                                              3)                                                                               -.890                                                                              4)                                                                               -2.626                                                                             5)                                                                               -.775                                   R 10.000                                                                             ANG                                                                               -.203                                                                              1)                                                                               -.010                                                                              2)                                                                               -.686                                                                              3)                                                                               -.908                                                                              4)                                                                               -2.649                                                                             5)                                                                               -.775                                   R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               -.021                                                                              2)                                                                               -.663                                                                              3)                                                                               -.927                                                                              4)                                                                               -2.673                                                                             5)                                                                               -.775                                   R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               -.036                                                                              2)                                                                               -.632                                                                              3)                                                                               -.952                                                                              4)                                                                               -2.705                                                                             5)                                                                               -.775                                   R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               -.056                                                                              2)                                                                               -.595                                                                              3)                                                                               -.985                                                                              4)                                                                               -2.746                                                                             5)                                                                               -.775                                   R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               -.078                                                                              2)                                                                               -.559                                                                              3)                                                                               -1.019                                                                             4)                                                                               -2.789                                                                             5)                                                                               -.775                                   R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               -.130                                                                              2)                                                                               -.491                                                                              3)                                                                               -1.092                                                                             4)                                                                               -2.879                                                                             5)                                                                               -.775                                   R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               -.176                                                                              2)                                                                               -.442                                                                              3)                                                                               -1.150                                                                             4)                                                                               -2.951                                                                             5)                                                                               -.775                                   Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephot End                                                           (126.0 mm) in Fifth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.543                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.203                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.617                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.692                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.795                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.931                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.073                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .Q00                                                                               3)                                                                               .000                                                                               4)                                                                               -4.380                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -4.632                                                                             5)                                                                               .000                                    Slope dx/da of Focus Cam at Telephoto End (126.0 mm) in Fifth Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               2.316                                                                              5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.203                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               2.140                                                                              5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               2.000                                                                              5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.828                                                                              5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.608                                                                              5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               1.379                                                                              5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .899                                                                               5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .468                                                                               5)                                                                               .000                                    Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (126.0 mm) in Fifth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -8.205                                                                             5)                                                                               .000                                    R 10.000                                                                             ANG                                                                               -.203                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -7.738                                                                             5)                                                                               .000                                    R 5.000                                                                              ANG                                                                               -.427                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -7.383                                                                             5)                                                                               .000                                    R 3.000                                                                              ANG                                                                               -.755                                                                              1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -6.939                                                                             5)                                                                               .000                                    R 2.000                                                                              ANG                                                                               -1.228                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -6.321                                                                             5)                                                                               .000                                    R 1.500                                                                              ANG                                                                               -1.788                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -5.615                                                                             5)                                                                               .000                                    R 1.000                                                                              ANG                                                                               -3.388                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -3.936                                                                             5)                                                                               .000                                    R .800                                                                               ANG                                                                               -5.500                                                                             1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               -2.168                                                                             5)                                                                               .000                                    __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.31,         γ.sub.aR /γ.sub.a0 = 0.26                                    

As can be seen from Tables 57, 58, and 59, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

From Tables 57, 58, and 59, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.21 at the wide-angle end (F=28.8), ×0.22 at the middle position (F=70.0), and ×0.26 at the telephoto end (F=126.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the fifth embodiment is calculated using formula (a), and is compared with that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

When the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0

    N.sub.W >14.6N.sub.M >16.1N.sub.T >16.9

Fifth Embodiment

    N.sub.W >8.5N.sub.M >8.4N.sub.T >7.3

Therefore, it can be seen that the numbers of divisions become small, compared to those in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

As described above, in the zoom lens of the fifth embodiment, since the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation becomes much smaller than that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 60, 61, and 62 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=28.8), middle position (F=70.0), and telephoto end (F=126.0) according to the first embodiment. In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 mm), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 60, 61, and 62, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and an object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 60, 61, and 62, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.80, -5.5), and it indicates that this position corresponds to the closest in-focus (R=0.80 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=0.80 m) object, and the tenth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.80 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the tenth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.80 m) object to an in-focus state at the object distance in the second column.

As described above, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μ is calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eight row, fourth column in first table: -0.214) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=0.80 m) in Table 60 is calculated by K_(a) =1.18/-5.5 =-0.214 using ΔBf=1.18 and Δa=-5.5. On the other hand, the value of the correction coefficient μ (eight row, fourth column in second table: 2.37) is calculated as μ=2.37 using ΔBf=1.18, K_(a) =-0.214, and γ_(a) =-0.428.

                                      TABLE 60                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (28.8 mm) of Fifth Embodiment          F = 28.8 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.204                                                                              5.000                                                                              -.427                                                                              3.000                                                                              -.755                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.428                                                                              .000    -.412   -.397   -.379                                       2  10.000  -.411                                                                              -.397                                                                              .000    -.383   -.367                                       3  5.000   -.396   -.383                                                                              -.371                                                                              .000    -.355                                       4  3.000   -.378   -.366   -.355                                                                              -.339                                                                              .000                                        5  2.000   -.355   -.344   -.333   -.318                                       6  1.500   -.331   -.320   -.310   -.296                                       7  1.000   -.271   -.262   -.253   -.241                                       8  .800    -.214   -.207   -.199   -.189                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.08                                                                               2.20                                                                               -.17                                                                               2.43                                                                               -.29                                                                               2.45                                        2  10.000                                                                             .08 2.20                                                                               .00 .00 -.09                                                                               2.62                                                                               -.20                                                                               2.50                                        3  5.000                                                                              .17 2.32                                                                               .09 2.50                                                                               .00 .00 -.12                                                                               2.46                                        4  3.000                                                                              .29 2.48                                                                               .20 2.65                                                                               .12 2.74                                                                               .00 .00                                         5  2.000                                                                              .44 2.56                                                                               .35 2.65                                                                               .27 2.61                                                                               .15 2.37                                        6  1.500                                                                              .59 2.60                                                                               .51 2.64                                                                               .42 2.58                                                                               .31 2.40                                        7  1.000                                                                              .92 2.51                                                                               .84 2.46                                                                               .75 2.36                                                                               .63 2.18                                        8  .800                                                                               1.18                                                                               2.37                                                                               1.10                                                                               2.29                                                                               1.01                                                                               2.19                                                                               .90 2.02                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.228                                                                             1.000                                                                              -1.788                                                                             1.000                                                                              -3.388                                                                             .800                                                                               -5.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.356   -.331   -.272   -.216                                       2  10.000  -.344   -.321   -.263   -.208                                       3  5.000   -.333   -.311   -.254   -.200                                       4  3.000   -.318   -.296   -.241   -.189                                       5  2.000                                                                              -.299                                                                              .000    -.278   -.224   -.175                                       6  1.500   -.278                                                                              -.257                                                                              .000    -.205   -.159                                       7  1.000   -.224   -.205                                                                              -.163                                                                              .000    -.124                                       8  .800    -.175   -.159   -.124                                                                              -.090                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.44                                                                               2.29                                                                               -.59                                                                               2.04                                                                               -.92                                                                               1.37                                                                               -1.19                                                                              .86                                         2  10.000                                                                             -.35                                                                               2.31                                                                               -.51                                                                               2.04                                                                               -.84                                                                               1.36                                                                               -1.10                                                                              .85                                         3  5.000                                                                              -.27                                                                               2.30                                                                               -.42                                                                               2.02                                                                               -.75                                                                               1.34                                                                               -1.02                                                                              .84                                         4  3.000                                                                              -.15                                                                               2.32                                                                               -.31                                                                               1.99                                                                               -.64                                                                               1.32                                                                               -.90                                                                               .82                                         5  2.000                                                                              .00 .00 -.16                                                                               1.89                                                                               -.48                                                                               1.28                                                                               -.75                                                                               .80                                         6  1.500                                                                              .16 2.23                                                                               .00 .00 -.33                                                                               1.26                                                                               -.59                                                                               .78                                         7  1.000                                                                              .48 1.93                                                                               .33 1.63                                                                               .00 .00 -.26                                                                               .70                                         8  .800                                                                               .75 1.79                                                                               .59 1.55                                                                               .26 1.11                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.50, K.sub.aR      /γ.sub.aR = 2.39                                                   

                                      TABLE 61                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (70.0 mm) of Fifth Embodiment         F = 70.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.196                                                                              5.000                                                                              -.410                                                                              3.000                                                                              -.729                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -2.610                                                                             .000    -2.533  -2.450  -2.333                                      2  10.000  -2.528                                                                             -2.450                                                                             .000    -2.371  -2.257                                      3  5.000   -2.442  -2.367                                                                             -2.290                                                                             .000    -2.178                                      4  3.000   -2.321  -2.249  -2.173                                                                             -2.066                                                                             .000                                        5  2.000   -2.161  -2.093  -2.022  -1.923                                      6  1.500   -1.996  -1.933  -1.868  -1.778                                      7  1.000   -1.632  -1.580  -1.526  -1.451                                      8  .800    -1.277  -1.234  -1.189  -1.126                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.50                                                                               14.70                                                                              -1.00                                                                              14.34                                                                              -1.70                                                                              13.15                                       2  10.000                                                                             .50 15.81                                                                              .00 .00 -.51                                                                               14.33                                                                              -1.20                                                                              13.02                                       3  5.000                                                                              1.00                                                                               15.51                                                                              .51 14.93                                                                              .00 .00 -.69                                                                               12.87                                       4  3.000                                                                              1.69                                                                               15.25                                                                              1.20                                                                               14.58                                                                              .69 13.60                                                                              .00 .00                                         5  2.000                                                                              2.58                                                                               15.00                                                                              2.09                                                                               14.35                                                                              1.59                                                                               13.58                                                                              .90 12.95                                       6  1.500                                                                              3.51                                                                               14.90                                                                              3.02                                                                               14.30                                                                              2.52                                                                               13.66                                                                              1.83                                                                               13.08                                       7  1.000                                                                              5.46                                                                               14.57                                                                              4.97                                                                               14.01                                                                              4.48                                                                               13.43                                                                              3.80                                                                               12.75                                       8  .800                                                                               7.02                                                                               13.75                                                                              6.54                                                                               13.18                                                                              6.05                                                                               12.59                                                                              5.37                                                                               11.82                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.195                                                                             1.500                                                                              -1.756                                                                             1.000                                                                              -3.344                                                                             .800                                                                               -5.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -2.177  -2.015  -1.652  -1.293                                      2  10.000  -2.105  -1.948  -1.597  -1.247                                      3  5.000   -2.031  -1.879  -1.539  -1.200                                      4  3.000   -1.927  -1.785  -1.461  -1.135                                      5  2.000                                                                              -1.793                                                                             .000    -1.664  -1.359  -1.049                                      6  1.500   -1.661                                                                             -1.543                                                                             .000    -1.250  -.956                                       7  1.000   -1.353  -1.247                                                                             -.987                                                                              .000    -.741                                       8  .800    -1.044  -.954   -.740                                                                              -.561                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -2.60                                                                              12.16                                                                              -3.54                                                                              11.58                                                                              -5.52                                                                              8.21                                                                               -7.11                                                                              5.46                                        2  10.000                                                                             -2.10                                                                              12.10                                                                              -3.04                                                                              11.59                                                                              -5.03                                                                              8.15                                                                               -6.62                                                                              5.42                                        3  5.000                                                                              -1.59                                                                              12.06                                                                              -2.53                                                                              11.62                                                                              -4.52                                                                              8.08                                                                               -6.11                                                                              5.37                                        4  3.000                                                                              -.90                                                                               12.05                                                                              -1.83                                                                              11.72                                                                              -3.82                                                                              7.97                                                                               -5.41                                                                              5.30                                        5  2.000                                                                              .00 .00 -.93                                                                               11.93                                                                              -2.92                                                                              7.76                                                                               -4.51                                                                              5.20                                        6  1.500                                                                              .93 12.62                                                                              .00 .00 -1.98                                                                              7.46                                                                               -3.58                                                                              5.09                                        7  1.000                                                                              2.91                                                                               11.83                                                                              1.98                                                                               10.31                                                                              .00 .00 -1.60                                                                              5.00                                        8  .800                                                                               4.49                                                                               10.74                                                                              3.57                                                                               9.34                                                                               1.60                                                                               6.39                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.49, K.sub.aR      /γ.sub.aR = 2.30                                                   

                                      TABLE 62                                     __________________________________________________________________________     Conversion Coefficient K.sub.a : (rs), γ.sub.a : (r) Associated          with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (126.0 mm) of Fifth Embodiment          F = 126.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               -.203                                                                              2.777                                                                              5.000                                                                              -.427                                                                              3.000                                                                              -.755                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -8.209                                                                             .000    -7.975  -7.761  -7.500                                      2  10.000  -7.943                                                                             -7.742                                                                             .000    -7.554  -7.325                                      3  5.000   -7.708  -7.534                                                                             -7.387                                                                             .000    -7.170                                      4  3.000   -7.437  -7.294  -7.160                                                                             -6.930                                                                             .000                                        5  2.000   -7.075  -6.951  -6.823  -6.614                                      6  1.500   -6.689  -6.581  -6.464  -6.276                                      7  1.000   -5.664  -5.576  -5.475  -5.310                                      8  .800    -4.602  -4.530  -4.444  -4.305                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -1.62                                                                              53.88                                                                              -3.31                                                                              65.46                                                                              -5.66                                                                              68.89                                       2  10.000                                                                             1.62                                                                               49.82                                                                              .00 .00 -1.69                                                                              74.73                                                                              -4.04                                                                              70.94                                       3  5.000                                                                              3.29                                                                               53.95                                                                              1.68                                                                               62.63                                                                              .00 .00 -2.35                                                                              67.91                                       4  3.000                                                                              5.62                                                                               59.75                                                                              4.02                                                                               69.57                                                                              2.35                                                                               76.44                                                                              .00 .00                                         5  2.000                                                                              8.69                                                                               62.90                                                                              7.12                                                                               69.69                                                                              5.47                                                                               71.55                                                                              3.13                                                                               68.60                                       6  1.500                                                                              11.96                                                                              64.62                                                                              10.43                                                                              69.54                                                                              8.80                                                                               70.43                                                                              6.48                                                                               68.73                                       7  1.000                                                                              19.19                                                                              61.91                                                                              17.76                                                                              63.48                                                                              16.22                                                                              62.65                                                                              13.98                                                                              59.84                                       8  .800                                                                               25.31                                                                              57.61                                                                              23.99                                                                              57.82                                                                              22.55                                                                              56.60                                                                              20.43                                                                              53.93                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -1.228                                                                             1.500                                                                              -1.788                                                                             1.000                                                                              -3.388                                                                             .800                                                                               -5.500                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -7.122  -6.691  -5.513  -4.326                                      2  10.000  -6.967  -6.553  -5.399  -4.232                                      3  5.000   -6.819  -6.417  -5.281  -4.132                                      4  3.000   -6.600  -6.220  -5.109  -3.988                                      5  2.000                                                                              -6.322                                                                             .000    -5.958  -4.866  -3.783                                      6  1.500   -6.000                                                                             -5.618                                                                             .000    -4.571  -3.543                                      7  1.000   -5.053  -4.716                                                                             -3.938                                                                             .000    -2.940                                      8  .800    -4.086  -3.807  -3.066                                                                             -2.167                                                                             .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -8.75                                                                              69.13                                                                              -11.97                                                                             62.65                                                                              -18.68                                                                             46.70                                                                              -23.79                                                                             23.87                                       2  10.000                                                                             -7.14                                                                              69.99                                                                              -10.39                                                                             62.40                                                                              -17.19                                                                             46.35                                                                              -22.41                                                                             23.52                                       3  5.000                                                                              -5.46                                                                              69.51                                                                              -8.74                                                                              61.42                                                                              -15.64                                                                             45.85                                                                              -20.96                                                                             23.11                                       4  3.000                                                                              -3.12                                                                              70.92                                                                              -6.43                                                                              59.98                                                                              -13.45                                                                             45.24                                                                              -18.92                                                                             22.51                                       5  2.000                                                                              .00 .00 -3.34                                                                              55.23                                                                              -10.51                                                                             44.59                                                                              -16.16                                                                             21.66                                       6  1.500                                                                              3.36                                                                               65.93                                                                              .00 .00 -7.31                                                                              45.49                                                                              -13.15                                                                             20.70                                       7  1.000                                                                              10.92                                                                              54.38                                                                              7.55                                                                               47.00                                                                              .00 .00 -6.21                                                                              17.39                                       8  .800                                                                               17.46                                                                              49.36                                                                              14.13                                                                              43.83                                                                              6.48                                                                               29.27                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.56, K.sub.aR      /γ.sub.aR = 2.00                                                   

As can be seen from Tables 60, 61, and 62 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) is considered, the rate of change becomes small as compared to the change in K_(a) (Tables 15, 16, and 17) in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 examined previously.

More specifically, the amount Δa of rotation for focusing in the first embodiment at the infinity object side becomes relatively smaller than that at the closest object side, as compared to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as the embodiment of Japanese Patent Application Laid-Open No. 5-142475. In fact, when the ratio between the amount of rotation for focusing upon focusing to the closest distance and the amount of rotation for focusing upon focusing to the object distance (R=5.0 m) is calculated in Tables 10 and 55, 4.296/10.0=0.430 in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, while -0.427/-5.5=0.078 in the fifth embodiment. As described above, when the focus cam with the arrangement of the present invention is used, since the amount Δa of rotation for focusing becomes relatively smaller at the infinity object side, the conversion coefficient K_(a) becomes relatively large at the infinity object side, and consequently, the change in conversion coefficient K_(a) in the direction of rotation can be reduced as compared to the conventional system.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the fifth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.55 are as follows.

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            4.76           0.34                                                 (F = 28.8)                                                                     Middle Position                                                                           5.78           0.31                                                 (F = 70.0)                                                                     Telephoto End                                                                             6.58           0.28                                                 (F = 126.0)                                                                    Fifth Embodiment                                                               Wide-angle End                                                                            0.50           2.39                                                 (F = 28.8)                                                                     Middle Position                                                                           0.49           2.30                                                 (F = 70.0)                                                                     Telephoto End                                                                             0.56           2.00                                                 (F = 126.0)                                                                    ______________________________________                                    

As described above, according to the present invention, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced, the value of the correction coefficient μ can be set to be large as compared to the defocus amount ΔBf, and at the same time, the change in correction coefficient μ can be decreased.

Therefore, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error in the conversion coefficient K_(a) calculated using γ_(a) and μ or in the actual lens driving amount Δa for focusing can be eliminated.

Next, in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the fifth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.55, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end (F=28.8), middle position (F=70.0), and telephoto end (F=126.0) are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -8.7%         -26.3%                                               (F = 28.8)                                                                     Middle Position                                                                           -13.2%         -23.4%                                               (F = 70.0)                                                                     Telephoto End                                                                             -14.1%         -28.7%                                               (F = 126.0)                                                                    Fifth Embodiment                                                               Wide-angle End                                                                             -6.9%         -2.4%                                                (F = 28.8)                                                                     Middle Position                                                                           -8.0%          -1.6%                                                (F = 70.0)                                                                     Telephoto End                                                                             -6.2%          -2.9%                                                (F = 126.0)                                                                    ______________________________________                                    

As described above, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Next, an examination will be made as to whether not only accurate auto-focusing but also so-called manual focusing can be attained in the zoom lens of the fifth embodiment.

Table 63 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 55) of the fifth embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 63 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 70.0, 95.0, and 126.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.80 m). Note that the amounts of rotation for focusing, which have values for eliminating any displacement of the imaging point at the wide-angle end and the telephoto end, are selected. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.8 m) in the respective zooming states with the focal lengths (F=28.8, 35.0, 50.0, 70.0, 95.0, and 126.0 mm). In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, fourth, and fifth lens units in turn from the right side. Note that the amount of movement in the direction of the optical axis toward the object side is represented by a positive value.

                                      TABLE 63                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Fifth Embodiment                              __________________________________________________________________________            0.80 m                                                                             1.00 m                                                                               1.50 m                                                                             2.00 m                                                                               3.00 m                                                                             5.00 m                                          __________________________________________________________________________     28.800 Bf                                                                             .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                            35.000 Bf                                                                             .000                                                                               .003  -.001                                                                              -.002 .005                                                                               .005                                            50.000 Bf                                                                             .000                                                                               .008  .006                                                                               -.002 -.003                                                                              -.001                                           70.000 Bf                                                                             .000                                                                               .044  .049                                                                               -.059 -.054                                                                              -.039                                           95.000 Bf                                                                             .000                                                                               -.092 -.012                                                                              .037  .039                                                                               .027                                            126.000 Bf                                                                            .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                            __________________________________________________________________________     ANGLE DA                                                                               -5.500                                                                              -3.388                                                                             -1.788                                                                              -1.228                                                                             -.755 -.427                                          __________________________________________________________________________     F 28.800 DX                                                                            .000 .000                                                                               .000 -.365                                                                              .000                                                                               R 0.80 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.533                                                                              .000                                                                               R 0.80 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -1.061                                                                             .000                                                                               R 0.80 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -2.019                                                                             .000                                                                               R 0.80 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -3.656                                                                             .000                                                                               R 0.80 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -6.367                                                                             .000                                                                               R 0.80 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.284                                                                              .000                                                                               R 1.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.417                                                                              .000                                                                               R 1.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.826                                                                              .000                                                                               R 1.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -1.590                                                                             .000                                                                               R 1.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -2.880                                                                             .000                                                                               R 1.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -4.956                                                                             .000                                                                               R 1.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.183                                                                              .000                                                                               R 1.50 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.268                                                                              .000                                                                               R 1.50 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.533                                                                              .000                                                                               R 1.50 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -1.035                                                                             .000                                                                               R 1.50 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -3.190                                                                             .000                                                                               R 1.50 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.135                                                                              .000                                                                               R 2.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.198                                                                              .000                                                                               R 2.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.396                                                                              .000                                                                               R 2.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.771                                                                              .000                                                                               R 2.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -1.355                                                                             .000                                                                               R 2.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -2.352                                                                             .000                                                                               R 2.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.089                                                                              .000                                                                               R 3.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.128                                                                              .000                                                                               R 3.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.260                                                                              .000                                                                               R 3.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.511                                                                              .000                                                                               R 3.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -.886                                                                              .000                                                                               R 3.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -1.542                                                                             .000                                                                               R 3.00 m                                         F 28.800 DX                                                                            .000 .000                                                                               .000 -.052                                                                              .000                                                                               R 5.00 m                                         F 35.000 DX                                                                            .000 .000                                                                               .000 -.075                                                                              .000                                                                               R 5.00 m                                         F 50.000 DX                                                                            .000 .000                                                                               .000 -.154                                                                              .000                                                                               R 5.00 m                                         F 70.000 DX                                                                            .000 .000                                                                               .000 -.305                                                                              .000                                                                               R 5.00 m                                         F 95.000 DX                                                                            .000 .000                                                                               .000 -.524                                                                              .000                                                                               R 5.00 m                                         F 126.000 DX                                                                           .000 .000                                                                               .000 -.913                                                                              .000                                                                               R 5.00 m                                         __________________________________________________________________________

As can be seen from Table 63, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Sixth Embodiment!

The sixth embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.95 m) to the amount of rotation for zooming from the wide-angle end (F=24.7) to the telephoto end (F=194.0) is set to be -0.80.

Table 64 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the sixth embodiment.

The upper table in Table 64 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the sixth embodiment in association with six zooming states (focal length F=24.7 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 85.0 (4-POS), 135.0 (5-POS), and 194.0 mm (6-POS)).

The middle table in Table 64 summarizes spline sample data when the shape of the focus cam in the second lens unit of the sixth embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 64 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=24.7, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) using the focus cam of the sixth embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=24.7) to the telephoto end (F=194.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.95 m) is set to be -8.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the fourth embodiment is -0.80.

                                      TABLE 64                                     __________________________________________________________________________     Second Embodiment F = 24.7 to 194.0 (Rotation                                  Amount Ratio: a.sub.F /a.sub.Z = -0.80)                                        __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Sixth             Embodiment                                                                              1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                               6-POS                                          __________________________________________________________________________            F 24.7000                                                                            35.0000                                                                             50.0000                                                                            85.0000                                                                             135.0000                                                                            194.0000                                       F1                                                                               83.0000                                                                             D1                                                                               8.4075                                                                             15.4045                                                                             23.5767                                                                            34.4070                                                                             43.3980                                                                             49.1234                                        F2                                                                               -15.0000                                                                            D2                                                                               28.3223                                                                            23.1584                                                                             19.2184                                                                            14.3263                                                                             10.2768                                                                             6.6130                                         F3                                                                               44.0000                                                                             D3                                                                               8.1372                                                                             7.7418                                                                              7.2728                                                                             5.5880                                                                              5.1884                                                                              4.7906                                         F4                                                                               60.0000                                                                             D4                                                                               55.0055                                                                            63.1527                                                                             71.4749                                                                            84.9444                                                                             94.8409                                                                             101.9854                                       __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding              to Sixth Embodiment                                                               ANGLE     (1)                                                                               (2)       (3)                                                                               (4)                                               __________________________________________________________________________     1  -10.0000  .0000                                                                             .5780     .0000                                                                             .0000                                             2  -8.0000   .0000                                                                             .5191     .0000                                                                             .0000                                             3  -5.1006   .0000                                                                             .4059     .0000                                                                             .0000                                             4  -3.6046   .0000                                                                             .3218     .0000                                                                             .0000                                             5  -2.4342   .0000                                                                             .2392     .0000                                                                             .0000                                             6  -1.4844   .0000                                                                             .1580     .0000                                                                             .0000                                             7  -.8361    .0000                                                                             .0942     .0000                                                                             .0000                                             8  .0000     .0000                                                                             .0000     .0000                                                                             .0000                                             9  .5000     .0000                                                                             -.0640    .0000                                                                             .0000                                             10 2.0000    .0000                                                                             -.2910    .0000                                                                             .0000                                             11 4.8994    .0000                                                                             -.9968    .0000                                                                             .0000                                             12 6.3953    .0000                                                                             -1.5990   .0000                                                                             .0000                                             13 7.5658    .0000                                                                             -2.2827   .0000                                                                             .0000                                             14 8.5156    .000                                                                              -3.0883   .0000                                                                             .0000                                             15 9.1639    .000                                                                              -3.8748   .0000                                                                             .0000                                             16 10.0000   .000                                                                              -5.5825   .0000                                                                             .0000                                             17 11.0000   .0000                                                                             -9.9000   .0000                                                                             .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Sixth Embodiment                                                               (Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.80)                              __________________________________________________________________________                    Infinity         Amount of                                                     Correspond-                                                                          Photograph-                                                                               Rotation for                                   Focal Length   ing Position                                                                         ing Distance                                                                              Focusing                                       __________________________________________________________________________     24.7 mm        .0000  5.00 m    -.836                                          35.0 mm        1.4533                                                                                3.00 m    -1.484                                         50.0 mm        3.3444                                                                                2.00 m    -2.434                                         85.0 mm        6.1312                                                                                1.50 m    -3.605                                         135.0 mm       8.6279                                                                                1.20 m    -5.101                                         194.0 mm       10.0000                                                                               0.95 m    -8.000                                         Condition Corresponding Value (1)                                                                    2.18                                                     Condition Corresponding Value (2)                                                                    10.19                                                    Condition Corresponding Value (3)                                                                   -0.80                                                     Condition Corresponding Value (4)                                                                    0.26 (wide-angle end)                                                          0.12 (telephoto end)                                     Condition Corresponding Value (5)                                                                    0.55 (wide-angle end)                                                          0.80 (telephoto end)                                     Condition Corresponding Value (6)                                                                    1.98 (wide-angle end)                                                          1.85 (telephoto end)                                     __________________________________________________________________________

Table 65 below summarizes the numerical value data of the cams of the focusing lens unit in the sixth embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 64. Note that the meanings of the reference symbols in Table 65 are the same as those in the fifth embodiment.

                  TABLE 65                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Sixth                        Embodiment                                                                                       Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)       F        ANGLE  (2)    F                                      ______________________________________                                         -8.0000                                                                               .5191     .0000                                                         -7.5000                                                                               .5029     .0000                                                         -7.0000                                                                               .4856     .0000                                                         -6.5000                                                                               .4670     .0000                                                         -6.0000                                                                               .4468     .0000                                                         -5.5000                                                                               .4249     .0000                                                         -5.0000                                                                               .4009     .0000                                                         -4.5000                                                                               .3747     .0000                                                         -4.0000                                                                               .3462     .0000                                                         -3.5000                                                                               .3151     .0000                                                         -3.0000                                                                               .2812     .0000                                                         -2.5000                                                                               .2443     .0000                                                         -2.0000                                                                               .2038     .0000                                                         -1.5000                                                                               .1595     .0000                                                         -1.0000                                                                               .1110     .0000                                                         -.5000 .0581     .0000                                                         .0000  .0000     24.7000  .0000  .0000  24.7000                                .5000  -.0640    28.1820  .5000  .9557  28.1820                                1.0000 -.1332    31.7391  1.0000 1.9059 31.7391                                1.5000 -.2084    35.3374  1.5000 2.8823 35.3374                                2.0000 -.2910    38.9843  2.0000 3.9161 38.9843                                2.5000 -.3824    42.7873  2.5000 5.0190 42.7873                                3.0000 -.4844    46.8974  3.0000 6.2000 46.8974                                3.5000 -.5985    51.4940  3.5000 7.4659 51.4940                                4.0000 -.7264    56.7072  4.0000 8.8121 56.7072                                4.5000 -.8699    62.5219  4.5000 10.2142                                                                               62.5219                                5.0000 -1.0306   68.8723  5.0000 11.6417                                                                               68.8723                                5.5000 -1.2111   75.6992  5.5000 13.0715                                                                               75.6992                                6.0000 -1.4162   83.0056  6.0000 14.4965                                                                               83.0056                                6.5000 -1.6509   90.7764  6.5000 15.9065                                                                               90.7764                                7.0000 -1.9215   99.1459  7.0000 17.3051                                                                               99.1459                                7.5000 -2.2373   108.3906 7.5000 18.7079                                                                               108.3906                               8.0000 -2.6106   118.8434 8.0000 20.1317                                                                               118.8434                               8.5000 -3.0721   131.3527 8.5000 21.6429                                                                               131.3527                               9.0000 -3.6548   146.7241 9.0000 23.2762                                                                               146.7241                               9.5000 -4.3955   165.4668 9.5000 25.0563                                                                               165.4668                               10.0000                                                                               -5.5825   194.0000 10.0000                                                                               27.5064                                                                               194.0000                               ______________________________________                                    

The left table in Table 65 summarizes the numerical value data of the focus cam of the sixth embodiment, and the right table in Table 65 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 64.

Tables 66, 67, and 68 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=24.7), the middle position (F=85.0), and the telephoto end (F=194.0) according to the sixth embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the sixth embodiment.

                                      TABLE 66                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle End (24.7 mm) in Sixth Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.399                                                                              1)                                                                               .000                                                                               2)                                                                               .047                                                                               3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               .094                                                                               3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               .158                                                                               3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               .239                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               .322                                                                               3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               .406                                                                               3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               .519                                                                               3)                                                                               .000 4)                                                                               .000                                         Imaging Magnification β.sub.K of Lens Units at Wide-angle End (24.7       mm) in Sixth                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.252                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R 10.000                                                                             ANG                                                                               -.399                                                                              1)                                                                               -.008                                                                              2)                                                                               -.249                                                                              3)                                                                               -14.202                                                                             4)                                                                               .083                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               -.017                                                                              2)                                                                               -.245                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               -.029                                                                              2)                                                                               -.241                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               -.046                                                                              2)                                                                               -.236                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               -.063                                                                              2)                                                                               -.230                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             i)                                                                               -.082                                                                              2)                                                                               -.225                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               -.108                                                                              2)                                                                               -.217                                                                              3)                                                                               -14.203                                                                             4)                                                                               .083                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle                                                             End (24.7 mm) in Sixth Embodiment                                              R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               1.309                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.399                                                                              1)                                                                               .000                                                                               2)                                                                               1.311                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               1.314                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               1.316                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               1.320                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               1.324                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               1.327                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.332                                                                              3)                                                                               .000 4)                                                                               .000                                         Slope dx/da of Focus Cam at Wide-angle End (24.7 mm) in Sixth Embodiment       R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.122                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.399                                                                              1)                                                                               .000                                                                               2)                                                                               -.113                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               -.104                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               -.093                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               -.078                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               -.064                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               -.049                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.032                                                                              3)                                                                               .000 4)                                                                               .000                                         Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (24.7 mm) in Sixth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.160                                                                              3)                                                                               .000 4)                                                                               .000                                         R 10.000                                                                             ANG                                                                               -.399                                                                              1)                                                                               .000                                                                               2)                                                                               -.148                                                                              3)                                                                               .000 4)                                                                               .000                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               -.137                                                                              3)                                                                               .000 4)                                                                               .000                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               -.122                                                                              3)                                                                               .000 4)                                                                               .000                                         R 2.000                                                                              ANG                                                                               -3.434                                                                             1)                                                                               .000                                                                               2)                                                                               -.103                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               -.084                                                                              3)                                                                               .000 4)                                                                               .000                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               -.065                                                                              3)                                                                               .000 4)                                                                               .000                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.042                                                                              3)                                                                               .000 4)                                                                               .000                                         __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.02,         γ.sub.aR /γ.sub.a0 = 0.26                                    

                                      TABLE 67                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle                                                                         Position (85.0 mm) in Sixth Embodiment                                         R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.395                                                                              1)                                                                               .000                                                                               2)                                                                               .170                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.827                                                                              1)                                                                               .000                                                                               2)                                                                               .337                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.470                                                                             1)                                                                               .000                                                                               2)                                                                               .555                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.411                                                                             1)                                                                               .000                                                                               2)                                                                               .822                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.579                                                                             1)                                                                               .000                                                                               2)                                                                               1.082                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.105                                                                             1)                                                                               .000                                                                               2)                                                                               1.338                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               1.667                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Unit at Middle Position (85.0       mm) in Sixth                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.447                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 10.000                                                                             ANG                                                                               -.395                                                                              1)                                                                               -.008                                                                              2)                                                                               -.435                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 5.000                                                                              ANG                                                                               -.827                                                                              1)                                                                               -.017                                                                              2)                                                                               -.424                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 3.000                                                                              ANG                                                                               -1.470                                                                             1)                                                                               -.030                                                                              2)                                                                               -.410                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 2.000                                                                              ANG                                                                               -2.411                                                                             1)                                                                               -.047                                                                              2)                                                                               -.392                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 1.500                                                                              ANG                                                                               -3.579                                                                             1)                                                                               -.065                                                                              2)                                                                               -.374                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R 1.200                                                                              ANG                                                                               -5.105                                                                             1)                                                                               -.085                                                                              2)                                                                               -.357                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               -.114                                                                              2)                                                                               -.335                                                                              3)                                                                               5.517                                                                              4)                                                                               -.416                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle                                                                 Position (85.0 mm) in Sixth Embodiment                                         R .000                                                                               ANG                                                                               -.000                                                                              1)                                                                               .000                                                                               2)                                                                               4.211                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.395                                                                              1)                                                                               .000                                                                               2)                                                                               4.264                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.827                                                                              1)                                                                               .000                                                                               2)                                                                               4.314                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.470                                                                             1)                                                                               .000                                                                               2)                                                                               4.378                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.411                                                                             1)                                                                               .000                                                                               2)                                                                               4.453                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.579                                                                             1)                                                                               .000                                                                               2)                                                                               4.523                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.105                                                                             1)                                                                               .000                                                                               2)                                                                               4.588                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               4.668                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Middle Position (85.0 mm) in Sixth                 Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.454                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.395                                                                              1)                                                                               .000                                                                               2)                                                                               -.408                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.827                                                                              1)                                                                               .000                                                                               2)                                                                               -.365                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.470                                                                             1)                                                                               .000                                                                               2)                                                                               -.315                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.411                                                                             1)                                                                               .000                                                                               2)                                                                               -.254                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.579                                                                             1)                                                                               .000                                                                               2)                                                                               -.195                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.105                                                                             1)                                                                               .000                                                                               2)                                                                               -.145                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.087                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position                                                    (85.0 mm) in Sixth Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -1.912                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.395                                                                              1)                                                                               .000                                                                               2)                                                                               -1.741                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.827                                                                              1)                                                                               .000                                                                               2)                                                                               -1.577                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.470                                                                             1)                                                                               .000                                                                               2)                                                                               -1.378                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.411                                                                             1)                                                                               .000                                                                               2)                                                                               -1.131                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.579                                                                             1)                                                                               .000                                                                               2)                                                                               -.882                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.105                                                                             1)                                                                               .000                                                                               2)                                                                               -.663                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.405                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 1.11,         γ.sub.aR /γ.sub.a0 = 0.21                                    

                                      TABLE 68                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End (194.0 mm) in Sixth Embodiment                                   R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               .000                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.387                                                                              1)                                                                               .000                                                                               2)                                                                               .975                                                                               3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               1.708                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               2.494                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               3.300                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               3.983                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               4.586                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               5.291                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Imaging Magnification β.sub.K of Lens Units at Telephoto End (194.0       mm) in Sixth                                                                   Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -.795                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 10.000                                                                             ANG                                                                               -.387                                                                              1)                                                                               -.009                                                                              2)                                                                               -.730                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               -.017                                                                              2)                                                                               -.681                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               -.030                                                                              2)                                                                               -.628                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               -.047                                                                              2)                                                                               -.575                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               -.066                                                                              2)                                                                               -.529                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               -.087                                                                              2)                                                                               -.489                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               -.118                                                                              2)                                                                               -.442                                                                              3)                                                                               4.203                                                                              4)                                                                               -.700                                         Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto                                                              End (194.0 mm) in Sixth Embodiment                                             R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               3.189                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.387                                                                              1)                                                                               .000                                                                               2)                                                                               4.046                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               4.642                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               5.236                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               5.795                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               6.230                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               6.584                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               6.963                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Slope dx/da of Focus Cam at Telephot End (194.0 mm) in Sixth Embodiment        R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -3.120                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.387                                                                              1)                                                                               .000                                                                               2)                                                                               -2.002                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               -1.388                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               -1.044                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               -.697                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               -.488                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               -.332                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -.174                                                                              3)                                                                               .000                                                                               4)                                                                               .000                                          Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (194.0 mm) in Sixth Embodiment                                                 R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                               2)                                                                               -9.950                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 10.000                                                                             ANG                                                                               -.387                                                                              1)                                                                               .000                                                                               2)                                                                               -8.098                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 5.000                                                                              ANG                                                                               -.836                                                                              1)                                                                               .000                                                                               2)                                                                               -6.441                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 3.000                                                                              ANG                                                                               -1.484                                                                             1)                                                                               .000                                                                               2)                                                                               -5.466                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 2.000                                                                              ANG                                                                               -2.434                                                                             1)                                                                               .000                                                                               2)                                                                               -4.041                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.500                                                                              ANG                                                                               -3.605                                                                             1)                                                                               .000                                                                               2)                                                                               -3.041                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R 1.200                                                                              ANG                                                                               -5.101                                                                             1)                                                                               .000                                                                               2)                                                                               -2.187                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          R .950                                                                               ANG                                                                               -8.000                                                                             1)                                                                               .000                                                                               2)                                                                               -1.208                                                                             3)                                                                               .000                                                                               4)                                                                               .000                                          __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 2.18,         γ.sub.aR /γ.sub.a0 = 0.12                                    

As can be seen from Tables 66, 67, and 68, at each focal length, the conversion coefficient γ_(x) associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam, contrary to the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

From Tables 66, 67, and 68, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.26 at the wide-angle end (F=24.7), ×0.21 at the middle position (F=85.0), and ×0.12 at the telephoto end (F=194.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the second embodiment is calculated using formula (a), and is compared with that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

When the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0

    N.sub.W >16.1N.sub.M >15.8N.sub.T >13.7

Sixth Embodiment

    N.sub.W >7.3N.sub.M >8.5N.sub.T >11.6

Therefore, it can be seen that the numbers of divisions become small, compared to those in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

As described above, in the sixth embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is smaller than that in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 69, 70, and 71 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=24.7), middle position (F=85.0), and telephoto end (F=194.0) according to the sixth embodiment. The arrangements of the tables and reference symbols are the same as those in the fifth embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 69, 70, and 71, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 69, 70, and 71, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.95, -8.0), and it indicates that this position corresponds to the closest in-focus (R=0.95 m) corresponding position.

                                      TABLE 69                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (24.7 mm) in Sixth Embodiment          F = 24.7 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.399                                                                              5.000                                                                              -.836                                                                              3.000                                                                              -1.484                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -.160                                                                              .000    -.153   -.147   -.139                                       2  10.000  -.154                                                                              -.148                                                                              .000    -.142   -.134                                       3  5.000   -.148   -.143                                                                              -.137                                                                              .000    -.129                                       4  3.000   -.141   -.135   -.130                                                                              -.122                                                                              .000                                        5  2.000   -.131   -.126   -.120   -.113                                       6  1.500   -.120   -.115   -.110   -.103                                       7  1.200   -.107   -.103   -.098   -.092                                       8  .950    -.088   -.084   -.080   -.075                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.06                                                                               1.65                                                                               -.12                                                                               1.66                                                                               -.21                                                                               1.56                                        2  10.000                                                                             .06 1.70                                                                               .00 .00 -.06                                                                               1.71                                                                               -.15                                                                               1.56                                        3  5.000                                                                              .12 1.73                                                                               .06 1.73                                                                               .00 .00 -.08                                                                               1.53                                        4  3.000                                                                              .21 1.77                                                                               .15 1.76                                                                               .08 1.71                                                                               .00 .00                                         5  2.000                                                                              .32 1.76                                                                               .26 1.71                                                                               .19 1.61                                                                               .11 1.42                                        6  1.500                                                                              .43 1.71                                                                               .37 1.65                                                                               .30 1.54                                                                               .22 1.37                                        7  1.200                                                                              .55 1.67                                                                               .48 1.59                                                                               .42 1.49                                                                               .33 1.33                                        8  .950                                                                               .71 1.58                                                                               .64 1.49                                                                               .58 1.40                                                                               .49 1.26                                        __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.434                                                                             1.500                                                                              -3.605                                                                             1.200                                                                              -5.101                                                                             .950                                                                               -8.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -.127   -.115   -.103   -.083                                       2  10.000  -.123   -.111   -.099   -.080                                       3  5.000   -.119   -.107   -.095   -.077                                       4  3.000   -.112   -.101   -.089   -.072                                       5  2.000                                                                              -.103                                                                              .000    -.093   -.082   -.066                                       6  1.500   -.094                                                                              -.084                                                                              .000    -.074   -.059                                       7  1.200   -.084   -.075                                                                              -.065                                                                              .000    -.052                                       8  .950    -.068   -.060   -.052                                                                              -.042                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.31                                                                               1.32                                                                               -.42                                                                               1.13                                                                               -.52                                                                               .92 -.67                                                                               .68                                         2  10.000                                                                             -.25                                                                               1.31                                                                               -.36                                                                               1.12                                                                               -.46                                                                               .91 -.61                                                                               .67                                         3  5.000                                                                              -.19                                                                               1.28                                                                               -.30                                                                               1.10                                                                               -.40                                                                               .89 -.55                                                                               .67                                         4  3.000                                                                              -.11                                                                               1.24                                                                               -.21                                                                               1.08                                                                               -.32                                                                               .88 -.47                                                                               .66                                         5  2.000                                                                              .00 .00 -.11                                                                               1.07                                                                               -.22                                                                               .86 -.37                                                                               .65                                         6  1.500                                                                              .11 1.19                                                                               .00 .00 -.11                                                                               .82 -.26                                                                               .65                                         7  1.200                                                                              .22 1.17                                                                               .11 1.00                                                                               .00 .00 -.15                                                                               .66                                         8  .950                                                                               .38 1.10                                                                               .26 .93 .15 .76 .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.55, K.sub.aR      /γ.sub.aR = 1.98                                                   

                                      TABLE 70                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (85.0 mm) in Sixth Embodiment         F = 85.0 mm                                                                    __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.395                                                                              5.000                                                                              -.827                                                                              3.000                                                                              -1.470                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -1.912                                                                             .000    -1.795  -1.681  -1.538                                      2  10.000  -1.856                                                                             -1.741                                                                             .000    -1.630  -1.491                                      3  5.000   -1.796  -1.684                                                                             -1.576                                                                             .000    -1.443                                      4  3.000   -1.715  -1.608  -1.506                                                                             -1.378                                                                             .000                                        5  2.000   -1.607  -1.505  -1.409  -1.285                                      6  1.500   -1.478  -1.383  -1.291  -1.173                                      7  1.200   -1.329  -1.240  -1.156  -1.046                                      8  .950    -1.108  -1.032  -.959   -.865                                       __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.71                                                                               22.83                                                                              -1.39                                                                              20.87                                                                              -2.26                                                                              19.58                                       2  10.000                                                                             .73 24.85                                                                              .00 .00 -.70                                                                               20.65                                                                              -1.60                                                                              19.71                                       3  5.000                                                                              1.48                                                                               24.54                                                                              .73 22.39                                                                              .00 .00 -.93                                                                               19.97                                       4  3.000                                                                              2.52                                                                               24.47                                                                              1.73                                                                               22.64                                                                              .97 21.68                                                                              .00 .00                                         5  2.000                                                                              3.87                                                                               24.25                                                                              3.04                                                                               22.45                                                                              2.23                                                                               21.01                                                                              1.21                                                                               17.89                                       6  1.500                                                                              5.29                                                                               23.33                                                                              4.40                                                                               21.43                                                                              3.56                                                                               19.68                                                                              2.48                                                                               16.64                                       7  1.200                                                                              6.78                                                                               22.22                                                                              5.84                                                                               20.32                                                                              4.94                                                                               18.53                                                                              3.80                                                                               15.78                                       8  .950                                                                               8.86                                                                               21.06                                                                              7.85                                                                               19.27                                                                              6.88                                                                               17.56                                                                              5.65                                                                               15.19                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.411                                                                             1.500                                                                              -3.579                                                                             1.200                                                                              -5.105                                                                             .950                                                                               -8.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -1.366  -1.194  -1.020  -.796                                       2  10.000  -1.324  -1.155  -.985   -.767                                       3  5.000   -1.280  -1.115  -.948   -.737                                       4  3.000   -1.220  -1.058  -.897   -.695                                       5  2.000                                                                              -1.131                                                                             .000    -.976   -.824   -.637                                       6  1.500   -1.027                                                                             -.882                                                                              .000    -.744   -.575                                       7  1.200   -.913   -.783                                                                              -.663                                                                              .000    -.510                                       8  .950    -.753   -.645   -.545                                                                              -.405                                                                              .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -3.29                                                                              15.85                                                                              -4.27                                                                              12.08                                                                              -5.21                                                                              9.68                                                                               -6.37                                                                              6.59                                        2  10.000                                                                             -2.67                                                                              15.66                                                                              -3.68                                                                              11.88                                                                              -4.64                                                                              9.56                                                                               -5.84                                                                              6.52                                        3  5.000                                                                              -2.03                                                                              15.38                                                                              -3.07                                                                              11.62                                                                              -4.06                                                                              9.43                                                                               -5.29                                                                              6.45                                        4  3.000                                                                              -1.15                                                                              14.71                                                                              -2.23                                                                              11.20                                                                              -3.26                                                                              9.26                                                                               -4.54                                                                              6.34                                        5  2.000                                                                              .00 .00 -1.14                                                                              10.72                                                                              -2.22                                                                              9.14                                                                               -3.56                                                                              6.21                                        6  1.500                                                                              1.20                                                                               13.05                                                                              .00 .00 -1.14                                                                              9.27                                                                               -2.54                                                                              6.05                                        7  1.200                                                                              2.46                                                                               12.71                                                                              1.19                                                                               10.61                                                                              .00 .00 -1.48                                                                              5.68                                        8  .950                                                                               4.21                                                                               12.58                                                                              2.85                                                                               10.64                                                                              1.58                                                                               8.81                                                                               .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.58, K.sub.aR      /γ.sub.aR = 1.97                                                   

                                      TABLE 71                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (194.0 mm) in Sixth Embodiment          F = 194.0 mm                                                                   __________________________________________________________________________     (R, ANGLE) =                                                                          .000                                                                               .000                                                                               10.000                                                                             -.387                                                                              5.000                                                                              -.836                                                                              3.000                                                                              -.484                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               -9.949                                                                             .000    -8.337  -6.891  -5.730                                      2  10.000  -10.079                                                                            -8.097                                                                             .000    -6.609  -5.571                                      3  5.000   -9.704  -7.682                                                                             -6.441                                                                             .000    -5.534                                      4  3.000   -9.609  -7.677  -6.548                                                                             -5.466                                                                             .000                                        5  2.000   -9.436  -7.493  -6.308  -5.140                                      6  1.500   -9.170  -7.203  -5.997  -4.844                                      7  1.200   -8.799  -6.817  -5.614  -4.493                                      8  .950    -7.993  -6.050  -4.901  -3.865                                      __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -3.23                                                                              108.94                                                                             -5.76                                                                              82.57                                                                              -8.51                                                                              175.82                                      2  10.000                                                                             3.90                                                                               -300.11                                                                            .00 .00 -2.97                                                                              114.03                                                                             -6.11                                                                              316.75                                      3  5.000                                                                              8.11                                                                               328.89                                                                             3.45                                                                               67.21                                                                              .00 .00 -3.59                                                                              290.18                                      4  3.000                                                                              14.26                                                                              417.01                                                                             8.42                                                                               162.09                                                                             4.24                                                                               -256.10                                                                            .00 .00                                         5  2.000                                                                              22.97                                                                              445.08                                                                             15.34                                                                              205.66                                                                             10.08                                                                              488.95                                                                             4.88                                                                               81.86                                       6  1.500                                                                              33.05                                                                              422.06                                                                             23.17                                                                              209.83                                                                             16.60                                                                              240.82                                                                             10.27                                                                              90.19                                       7  1.200                                                                              44.88                                                                              388.16                                                                             32.13                                                                              203.11                                                                             23.94                                                                              186.33                                                                             16.25                                                                              91.23                                       8  .950                                                                               63.94                                                                              325.16                                                                             46.05                                                                              182.14                                                                             35.11                                                                              146.87                                                                             25.18                                                                              85.98                                       __________________________________________________________________________     (R, ANGLE) =                                                                          2.000                                                                              -2.434                                                                             1.500                                                                              -3.605                                                                             1.200                                                                              -5.101                                                                             .950                                                                               -8.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    -4.642  -3.779  -3.063  -2.237                                      2  10.000  -4.521  -3.678  -2.977  -2.168                                      3  5.000   -4.449  -3.599  -2.901  -2.102                                      4  3.000   -4.299  -3.461  -2.778  -2.002                                      5  2.000                                                                              -4.041                                                                             .000    -3.260  -2.606  -1.862                                      6  1.500   -3.809                                                                             -3.041                                                                             .000    -2.412  -1.705                                      7  1.200   -3.505  -2.773                                                                             -2.187                                                                             .000    -1.523                                      8  .950    -2.973  -2.319  -1.799                                                                             -1.209                                                                             .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -11.30                                                                             76.03                                                                              -13.62                                                                             56.13                                                                              -15.62                                                                             39.02                                                                              -17.90                                                                             21.03                                       2  10.000                                                                             -9.25                                                                              77.85                                                                              -11.83                                                                             56.48                                                                              -14.03                                                                             38.86                                                                              -16.51                                                                             20.79                                       3  5.000                                                                              -7.11                                                                              70.37                                                                              -9.96                                                                              54.30                                                                              -12.37                                                                             37.91                                                                              -15.06                                                                             20.37                                       4  3.000                                                                              -4.08                                                                              63.91                                                                              -7.34                                                                              53.20                                                                              -10.05                                                                             37.18                                                                              -13.04                                                                             19.88                                       5  2.000                                                                              .00 .00 -3.82                                                                              52.99                                                                              -6.95                                                                              36.33                                                                              -10.36                                                                             19.17                                       6  1.500                                                                              4.46                                                                               77.72                                                                              .00 .00 -3.61                                                                              35.12                                                                              -7.50                                                                              18.24                                       7  1.200                                                                              9.35                                                                               70.51                                                                              4.15                                                                               47.13                                                                              .00 .00 "4.42                                                                              16.98                                       8  .950                                                                               16.54                                                                              62.58                                                                              10.19                                                                              42.94                                                                              5.21                                                                               29.35                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.80, K.sub.aR      /γ.sub.aR = 1.85                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the sixth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.80 are as follows.

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity     Closest                                                           Arrangement K.sub.a0 /γ.sub.a0                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            6.14           0.31                                                 (F = 24.7)                                                                     Middle Position                                                                           7.63           0.31                                                 (F = 85.0)                                                                     Telephoto End                                                                             12.40          0.29                                                 (F = 194.0)                                                                    Sixth Embodiment                                                               Wide-angle End                                                                            0.55           1.98                                                 (F = 24.7)                                                                     Middle Position                                                                           0.58           1.97                                                 (F = 85.0)                                                                     Telephoto End                                                                             0.80           1.85                                                 (F = 194.0)                                                                    ______________________________________                                    

As described above, in the sixth embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the case in which the rotation amount ratio (a_(F) /a_(Z)) is set to be 1.0, as in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the sixth embodiment of the present invention in which said ratio (a_(F) /a_(Z)) is set to be -0.80, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         When the rotation amount ratio (a.sub.F /a.sub.Z) is set to be 1.0                      Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -11.4%        -29.7%                                               (F = 24.7)                                                                     Middle Position                                                                           -12.3%         -34.8%                                               (F = 85.0)                                                                     Telephoto End                                                                             -15.1%         -32.9%                                               (F = 194.0)                                                                    Sixth Embodiment                                                               Wide-angle End                                                                             -7.8%         -1.5%                                                (F = 24.7)                                                                     Middle Position                                                                           -8.7%          -2.0%                                                (F = 85.0)                                                                     Telephoto End                                                                             -6.2%          -2.6%                                                (F = 194.0)                                                                    ______________________________________                                    

As described above, in the sixth embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 72 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 64) of the sixth embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the fifth embodiment. The upper table in Table 72 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.2, and 0.95 m) in the respective zooming states of the focal lengths (F=24.7, 35.0, 50.0, 85.0, 135.0, and 194.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 72                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Sixth Embodiment                              __________________________________________________________________________             0.95 m                                                                             1.20 m                                                                               1.50 m                                                                             2.00 m                                                                               3.00 m                                                                             5.00 m                                         __________________________________________________________________________     F 24.700 Bf                                                                            .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           F 35.000 Bf                                                                            .000                                                                               .000  .000                                                                               .002  .002                                                                               .003                                           F 50.000 Bf                                                                            .000                                                                               .003  .007                                                                               .012  .005                                                                               .000                                           F 85.000 Bf                                                                            .000                                                                               .003  -.022                                                                              -.026 -.020                                                                              -.015                                          F 135.000 Bf                                                                           .000                                                                               -.049 -.048                                                                              -.047 -.053                                                                              -.063                                          F 194.000 Bf                                                                           .000                                                                               .000  .000                                                                               .000  .000                                                                               .000                                           __________________________________________________________________________     ANGLE DA                                                                               -8.000                                                                              -5.101                                                                             -3.605                                                                              -2.434                                                                               -1.484                                                                             -.836                                          __________________________________________________________________________     F 24.700 DX                                                                            .000 .519                                                                               .000 .000                                                                              R  0.95 m                                             F 35.000 DX                                                                            .000 .670                                                                               .000 .000                                                                              R  0.95 m                                             F 50.000 DX                                                                            .000 .945                                                                               .000 .000                                                                              R  0.95 m                                             F 85.000 DX                                                                            .000 1.667                                                                              .000 .000                                                                              R  0.85 m                                             F 135.000 DX                                                                           .000 3.128                                                                              .000 .000                                                                              R  0.95 m                                             F 194.000 DX                                                                           .000 5.291                                                                              .000 .000                                                                              R  0.95 m                                             F 24.700 DX                                                                            .000 .406                                                                               .000 .000                                                                              R  1.20 m                                             F 35.000 DX                                                                            .000 .526                                                                               .000 .000                                                                              R  1.20 m                                             F 50.000 DX                                                                            .000 .744                                                                               .000 .000                                                                              R  1.20 m                                             F 85.000 DX                                                                            .000 1.337                                                                              .000 .000                                                                              R  1.20 m                                             F 135.000 DX                                                                           .000 2.604                                                                              .000 .000                                                                              R  1.20 m                                             F 194.000 DX                                                                           .000 4.586                                                                              .000 .000                                                                              R  1.20 m                                             F 24.700 DX                                                                            .000 .322                                                                               .000 .000                                                                              R  1.50 m                                             F 35.000 DX                                                                            .000 .418                                                                               .000 .000                                                                              R  1.50 m                                             F 50.000 DX                                                                            .000 .593                                                                               .000 .000                                                                              R  1.50 m                                             F 85.000 DX                                                                            .000 1.087                                                                              .000 .000                                                                              R  1.50 m                                             F 135.000 DX                                                                           .000 2.170                                                                              .000 .000                                                                              R  1.50 m                                             F 194.000 DX                                                                           .000 3.983                                                                              .000 .000                                                                              R  1.50 m                                             F 24.700 DX                                                                            .000 .239                                                                               .000 .000                                                                              R  2.00 m                                             F 35.000 DX                                                                            .000 .310                                                                               .000 .000                                                                              R  2.00 m                                             F 50.000 DX                                                                            .000 .441                                                                               .000 .000                                                                              R  2.00 m                                             F 85.000 DX                                                                            .000 .828                                                                               .000 .000                                                                              R  2.00 m                                             F 135.000 DX                                                                           .000 1.705                                                                              .000 .000                                                                              R  2.00 m                                             F 194.000 DX                                                                           .000 3.300                                                                              .000 .000                                                                              R  2.00 m                                             F 24.700 DX                                                                            .000 .158                                                                               .000 .000                                                                              R  3.00 m                                             F 35.000 DX                                                                            .000 .205                                                                               .000 .000                                                                              R  3.00 m                                             F 50.000 DX                                                                            .000 .295                                                                               .000 .000                                                                              R  3.00 m                                             F 85.000 DX                                                                            .000 .559                                                                               .000 .000                                                                              R  3.00 m                                             F 135.000 DX                                                                           .000 1.202                                                                              .000 .000                                                                              R  3.00 m                                             F 194.000 DX                                                                           .000 2.494                                                                              .000 .000                                                                              R  3.00 m                                             F 24.700 DX                                                                            .000 .094                                                                               .000 .000                                                                              R  5.00 m                                             F 35.000 DX                                                                            .000 .121                                                                               .000 .000                                                                              R  5.00 m                                             F 50.000 DX                                                                            .000 .178                                                                               .000 .000                                                                              R  5.00 m                                             F 85.000 DX                                                                            .000 .340                                                                               .000 .000                                                                              R  5.00 m                                             F 135.000 DX                                                                           .000 .762                                                                               .000 .000                                                                              R  5.00 m                                             F 194.000 DX                                                                           .000 1.708                                                                              .000 .000                                                                              R  5.00 m                                             __________________________________________________________________________

As can be seen from Table 72, in the zoom lens of the sixth embodiment, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

As described above, in the embodiments, the present invention can be applied to zoom lens systems based on various lens unit arrangements or focusing lens units.

As described above, according to the present invention, in an inner focusing type zoom lens which is attached to, e.g., an auto-focusing camera which has focus detection means, storage means, calculation means, and the like, the number of data of specific coefficients (e.g., the conversion coefficient γ_(a) and the correction coefficient μ) required for auto-focusing can be reduced as compared to the conventional system, without making the barrel mechanism larger. Furthermore, an error upon calculation of the lens driving amount of the focusing lens unit using the stored specific coefficients in correspondence with the detected defocus amount can be reduced as compared to the conventional system.

In other words, when the arrangement of the present invention is adopted, since the rate of change of the conversion coefficient γ_(a) is reduced as compared to the conventional system, the number of data of the conversion coefficient γ_(a), the correction coefficient μ, and the like which are stored for calculating the lens driving amount for focusing can be reduced, and a cost reduction can be realized in terms of the storage capacity.

Furthermore, since the change in conversion coefficient K_(a) to the conversion coefficient γ_(a) becomes small, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced.

Therefore, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a certain lens arrangement range can be reduced.

In the present invention, the conversion coefficient γ_(a) at an in-focus point and the conversion coefficient μ which is defined by formula K_(a) =γ_(a) (1-ΔBf/μ) are set to be specific coefficients. Alternatively, a correction coefficient defined by a formula different from the above-mentioned formula may be set. Furthermore, the conversion coefficient γ_(a) need not always be set in correspondence with the sensitivity (dBf/da) associated with the direction of rotation at an in-focus point. As long as focusing accuracy can be improved, the sensitivity at a point other than the in-focus point and the corresponding correction coefficient may be set to be specific coefficients.

Note that the present invention can be applied to various other zoom lens systems based on lens unit arrangements or focusing lens units other than those in the above-mentioned embodiments, as a matter of course. 

What is claimed is:
 1. A zoom lens system in which a movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by an amount of movement, in a direction of an optical axis, of lens units, and an angle of rotation of a rotatable lens barrel, said zoom lens satisfying the following conditional formulas at least at the telephoto end:

    1.00<γ.sub.xR /γ.sub.xO

    4.50<ΔX.sub.TR /ΔX.sub.WR <10.00

    -1.00<a.sub.F /a.sub.Z <-0.60

where γ_(xO) : the ratio (dBf/dx) of an amount dBf of infinitesimal movement of an imaging plane to an amount dx of infinitesimal movement, in the direction of the optical axis, of said focusing lens unit at an infinity in-focus point γ_(xR) : the ratio (dBf/dx) of an amount dBf of infinitesimal movement of an imaging plane to an amount dx of infinitesimal movement, in the direction of the optical axis, of said focusing lens unit at a closest in-focus point Δx_(WR) : an amount of movement, in the direction of the optical axis, of said focusing lens unit required for focusing from an infinity position to a closest distance position at a wide-angle end Δx_(TR) : an amount of movement, in the direction of the optical axis, of said focusing lens unit required for focusing from an infinity position to a closest distance position at a telephoto end a_(Z) : an amount of rotation of said focusing lens unit on said focus cam corresponding to zooming from the wide-angle end to the telephoto end a_(F) : an amount of rotation corresponding to focusing from an infinity in-focus state to a closest in-focus state.
 2. A zoom lens system according to claim 1, wherein said zoom lens satisfies the following conditional formula at least at the wide-angle end and the telephoto end:

    0.13<γ.sub.aR /γ.sub.aO <0.80

where γ_(aO) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity in-focus point γ_(aR) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the closest in-focus point.
 3. A zoom lens system according to claim 2, wherein said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.50<K.sub.aO /γ.sub.aO <1.30

    0.80<K.sub.aR /γ.sub.aR <1.80

where K_(aO) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/μa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state K_(aR) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the closest in-focus state ΔBf: a defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: an angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object.
 4. A zoom lens system according to claim 1, wherein said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.50<K.sub.aO /γ.sub.aO <1.30

    0.80<K.sub.aR /γ.sub.aR <1.80

where γ_(aO) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity in-focus point γ_(aR) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the closest in-focus point K_(aO) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state K_(aR) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the closest in-focus state ΔBf: a defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: an angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object.
 5. A zoom lens system in which a movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by an amount of movement, in a direction of an optical axis, of lens units, and an angle of rotation of a rotatable lens barrel, said zoom lens satisfying the following conditional formulas at least at the telephoto end:

    1.00<γ.sub.xR /γ.sub.xO

    10.00<Δx.sub.TR /Δx.sub.WR <30.00

    -1.00<a.sub.F /a.sub.Z <-0.50

where γ_(xO) : the ratio (dBf/dx) of an amount dBf of infinitesimal movement of an imaging plane to an amount dx of infinitesimal movement, in the direction of the optical axis, of said focusing lens unit at an infinity in-focus point γ_(xR) : the ratio (dBf/dx) of an amount dBf of infinitesimal movement of an imaging plane to an amount dx of infinitesimal movement, in the direction of the optical axis, of said focusing lens unit at a closest in-focus point Δx_(WR) : an amount of movement, in the direction of the optical axis, of said focusing lens unit required for focusing from an infinity position to a closest distance position at a wide-angle end Δx_(TR) : an amount of movement, in the direction of the optical axis, of said focusing lens unit required for focusing from an infinity position to a closest distance position at a telephoto end a _(Z) : an amount of rotation of said focusing lens unit on said focus cam corresponding to zooming from the wide-angle end to the telephoto end a_(F) : an amount of rotation corresponding to focusing from an infinity in-focus state to a closest in-focus state.
 6. A zoom lens system according to claim 5, wherein said zoom lens satisfies the following conditional formula at least at the wide-angle end and the telephoto end:

    0.08<γ.sub.aR /γ.sub.aO <0.70

where γ_(aO) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity in-focus point γ_(aR) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the closest in-focus point.
 7. A zoom lens system according to claim 6, wherein said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.35<K.sub.aO /γ.sub.aO <1.00

    1.00<K.sub.aR /γ.sub.aR <3.00

where K_(aO) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state K_(aR) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the closest in-focus state ΔBf: a defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: an angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object.
 8. A zoom lens system according to claim 5, wherein said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.35<K.sub.aO /γ.sub.aO <1.00

    1.00<K.sub.aR /γ.sub.aR <3.00

where γ_(aO) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity in-focus point γ_(aR) : the ratio (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the closest in-focus point K_(aO) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state K_(aR) : the conversion coefficient K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the closest in-focus state ΔBf: a defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: an angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object. 